Unfortunately I am unable to recommend any other material, as the Ainu are outside of what my fields of study were in graduate school. With any luck, you'll shortly have some more robust recommendations from far more qualified individuals than I. In any case, I remember coming across this article when I was in school and found it to be an engaging read. Morris-Suzuki discusses how Ainu culture came to be defined and classified during the Tokugawa and Meiji periods by the Japanese, and how that process informed how Japanese culture and "Japaneseness" (to borrow a phrase from the article) was conceived during the same period. The discussion is brought into the present day as well (sort of anyway, since it was written in 1994). It turns out that it is available as a free PDF on the journal's website.
Hopefully you may find this helpful, despite the relatively limited scope of the piece.
Ancient Jomon of Japan (Junko Habu, 2004) covers the archaeology of pre-agricultural Japan in great detail. The book mainly focuses on Tohoku, but includes some information on Hokkaido as well. As Jomon culture would influence later culture around the Sea of Okhotsk (including the Ainu), and very little other English language literature is available on the subject, I'd strongly strongly recommend picking up this book if you have the chance.
The Conquest of Ainu Lands (Brett Walker, 2001) primarily covers over two centuries of Ainu history (1590-1800), reflecting on how Early-Modern northward Japanese expansion transformed and diminished Ainu culture, as well as going into great depth on the economics of Ainu society at this time. While primarily focused on Hokkaido, two chapters are also devoted to Sakhalin and the Kurils respectively. It does give an overview of Ainu culture, but this is a secondary focus.
Steller's History of Kamchatka (Georg Steller & Marvin Falk, 2003) is an English language translation of Georg Steller's famous historical and anthropological work in Kamchatka in the 1740s. Steller was a biologist by profession, and devotes most of the work to the climate and environment of Kamchatka. He does describe Kamchatkan history up to Russian contact, and offers a rich description of Itelmen culture. He also documents interaction between the Itelmen and the Ainu--the later of which were highly involved in oceanic trade.
I would like to emphasize that while of great worth as an unusually old primary source, this book is outdated. Steller makes some suggestions which are now known to be inaccurate. He also held a noticeably racist attitude against the Itelmen, conferring hefty bias upon his descriptions of their culture.
Race, Resistance, and the Ainu of Japan (Richard Siddle, 1996) is just as much a work of modern sociology as it is one of modern history, concerning the evolution of race relations between the Ainu and Japanese. With the colossal impact of Japanese colonialism, genocide, and racial discrimination on Ainu culture, it does a fantastic job at discussing 'their status today.'
The Ainu of Japan (John Batchelor, 1892) was written as Japanese Industrialization was underway, and Hokkaido was in the processed of being thoroughly Japonized. A comprehensive view of Ainu culture as it evolved at breakneck pace in the late 1800s, it's straight up fun to read.
Lastly, I'd like to mention one book which I haven't read. 'Ainu: Spirit of a Northern People' has received fantastic reviews for its coverage of Ainu culture and abundant illustrations, and I hope to be able to read it soon, but as I do not have access to the book I can't comment on it personally.
"Alone with the Hairy Ainu" by AH Savage Landor. Landor travels to Hokkaido and the Kuril islands in exploration. It was written during the Meji era by a European so buckle up for some Euro-centrism. Some parts of it arent believable such as a tryst between him and a native hottie. But it's an Interesting tale none the less. Very informative because it is a primary source of a European experiencing non-Yamato Japan. There's lots of detailed sketches (Landor is quite the artist). Lots of background and hypothesixing of earlier inhabitants that tickle my curiosity (questions we still haven't answered). Enough historic context to make it known why the Ainu of the Kuril suffered and are virtually extinct. While he thinks himself more civilized, his clothes eventually get destroyed by the elements and he offers a detailed portrait of Ainu life. I read it for a class on ethnographic by foreigners on Japan.