On Aug 1 1943 during the raid on Ploesti a B-24 Liberator "The Witch" was shot down in Yugoslavia. 4 Crew members evaded capture for 319 days until OSS recovered them. Has anyone ever told or recorded their stories?

So, as far as it is possible to say, there is no specific account of the story of these four American air men or any other Allied pilot shot down over Yugoslavia about their time with Tito's Yugoslav Partisans. The Texan newspaper Star Telegram has an article about one of the Crew Members of that airplane – Dale Hulsey, one of the gunners – here. It mentions that Hulsey hardly ever talked about his experience but that he and the others had a couple of reunions after the war

It is rather scant on the details that involves their time with the Partisans. There is also an article about Gillette here that I can't access in Europe. Also, there seems to be scant literature on the 98th Bomb Group outside of some general works on USAF units in WWII.

Now, it is of course almost impossible to say why none of the men involved in that particular mission and who then spent so much time with the Partisans never wrote an autobiography or similar text about their experience but a quick look at the English-language / American historiography on Tito's Partisans tells a rather peculiar story about the likely reasons, this story was never much part of it.

In short, American historiography on the subject was more interested in re-fighting the Yugoslav civil war that occurred during the Axis occupation of Yugoslavia and within that conflict coming down hard on the side of Draža Mihailović instead of Tito and his Partisans, meaning it tended to focus on explaining away how Mihailović and his Chetniks had collaborated with the Axis and had lost the support of the Western Allied governments in 1943/44 while being rather quiet on the feats of the Partisans and treating them rather with a weariness that stemmed from anti-communist sentiments, at least until the 70s.

The cliff notes version here is that during the Axis occupation and subsequent dismemberment of the Kingdom of Yugoslavia in 1941 and subsequent years of the war, the country underwent not just a brutal insurgency and counter-insurgency of various forces fighting the Axis but a veritable civil war about the political and social future of Yugoslavia (indeed, a war about the question whether Yugoslavia would continue to exist). While many forces, such as the Axis aligned Croatian Ustasha regime, were involved in said conflict, the major players on the side of the resistance initially were the Yugoslav Partisans, lead by Josip Broz Tito and the Communist Party, and the so-called Chetniks, lead by Draža Mihailović and aligned with the Yugoslav royal government in exile in London.

While the two forces initially collaborated in the so-called Serbia uprising in 1941 in their fight against the Germans in Serbia, soon political as well as strategic disagreements began to surface. The Partisans embraced a strategy of national liberation that involved all the different nationalities such as Croats, Slovenes, Serbs, and Bosnians in Yugoslavia on equal footing while the Chetniks were a distinctly royalist and thereby very Serbian political force, embracing Serb supremacy in form of the Monarchy over other nationalities in Yugoslavia. Furthermore, the Partisans followed a strategy of constant and permanent guerilla warfare, aiming at attacking and sabotaging Axis rule however they could. The Chetniks on the other hand were a force that was very local in its character, meaning unlike the Partisans, which represented a very mobile force, ready to move wherever they had the easiest time harrying the Axis, a lot of the Chentiks preferred to stay with their local communities. This translated, much due to the horrible policy of German reprisals for guerilla attacks against them, into a strategy that was more focused on survival and keeping still and waiting for a potential Allied landing in the Balkans as had happened in WWI.

Initially the Western Allied governments all supported Mihailović as the "legitimate" and official Yugoslav resistance due to the fact that the Yugoslav government in exile officially supported him, even going so far as making him its minister of war. Only Stalin in Moscow lend tacit aid to the Partisans but even the Soviets officially recognized Mihailović. This began to change over the course of 1942 and 1943 because the conflict between the Partisans and Chetniks began to escalate. Militarily weaker than the Partisans and due to its royalist policies only having a political foothold in Serbia, Mihailović began collaborating with various Axis powers, at first especially Italy, against the Partisans. Despite the presence of various Allied missions with his command such as an OSS mission, the Chetniks participated in what the Germans called "Case White", an offensive against Partisan troops in Montenegro that resulted in the battle of the Neretva.

While there still was collaboration between the OSS and Mihailović in 1944 – also in the rescue of downed Allied airmen in Operation Halyard –, the British had concluded in December 1943 that Mihailović's cooperation with the Italians and partly the Germans had went beyond the acceptable and the Western Allies slowly shifted their support to Tito's Partisans as the force that did the most damage to the Axis in the region. With the Partisan victory in Yugoslavia in 1944 and subsequent German retreat, Mihailović also fled and was later captured in 1946 while hiding and attempting to build a new resistance movement against the Tito government. He was tried by the new government and sentenced to death.

Already around this time and under the new political circumstance of the emerging Cold War, a specific narrative around the Yugoslav war began to emerge in the United States. The so-called Committee for a fair trial for Draža Mihailović had formed and began protesting the Tito government, highlighting the partial and sometimes successful collaboration of Mihailović and Western forces. At this time, the Tito government was staunchly aligned with Stalin's USSR and would remain so for two more years until the Tito-Stalin split changed the political realities in the Balkans, almost leading to socialist Yugoslavia becoming aligned with NATO but due to Stalin's death instead founding the Non-Aligned Movement. But while the split between socialist Yugoslavia and the USSR lead to massive political and financial aid of the US for the Tito government, the public narrative of the war was one that focused strongly on Mihailović and his good deeds over the Partisans.

A lot of ink was spilled that painted the Partisans as the "bad guys" of the conflict until the 1973 publication of Walter Roberts' book Tito, Mihailović and the Allies, 1941-1945. Roberts was a foreign service official and his book sketched out the Western Allied policy towards both Tito and Mihailović during the course of the war, including the American and British missions to both of them and the problem of Mihailović's collaboration. After Roberts and with the public image of socialist Yugoslavia slowly changing in the course of the 70s, various more books that focused on a more objective picture of the conflict emerged. Among them Jozo Tomasevich's 1975 War and Revolution in Yugoslavia, 1941–1945: The Chetniks., the first volume of a planned three volume history of the war in Yugoslavia by the Yugoslav (and later American) scholar.

While in subsequent years, a couple of accounts of those who had served with the Partisans in WWII would emerge, such as Franklin Lindsay's A Beacon in the Night – Lindsay was an OSS officer that had served with the Partisans and has written in glowing terms about them –, such publications would remain sparse, especially once Yugoslavia began to violently disintegrate in the early 1990s. This lead to a whole wave of publications that went to portray the Balkans in general and Yugoslavia especially as a place of ancient and unsolvable ethnic hatred and brutality and left once again little room in the public discourse for highlighting positive deeds by communist Partisans.

This specific trend continues – somewhat – to this day in parts of the English language scholarship on Yugoslavia. In 2010 Marcia Christoff Kurapovna published Shadows on the Mountains about the Allied cooperation with Mihailović that portrayed him in the most positive light while the Partisans are described as bloodthristy Bolsheviks. Even the more even-handed Andrew Buchanan in his 2014 book American Grand Strategy in the Mediterranean during World War II decries the "radical" Partisans vs. the more prudent Mihailović Chetniks (what is so radical about fighting the Axis and what is so prudent about collaborating with them, I do not know). There are of course exceptions to this – such as the scholarship by Sabrina P. Ramet, who focuses on national building in Yugoslavia and has written about collaboration in Serbia in general – but the general trend is that a lot of the authors interested in writing a more military focused history of WWII in Yugoslavia tend to focus overly on Mihailović and his Chentiks while the Partisans are usually portrayed in a more negative light.

This leaves little room or interest in stories such as American Air Men saved by the Partisans and fighting with them and since the survivors of that particular plane seem to have not been interested in writing down their stories, it had remained removed in greater detail from the official historiography. Stories of saved air men usually concentrate on the brief collaboration with the Chetniks but tend to leave out the Partisans as a force that did the same altogether. So, in short, the political nature of American historiography of WWII is certainly a factor in why there isn't much more information on this story.