I have posted this several times, to no avail, I am however hoping someone can help. I am very interested in this and have been looking on and off. I have not been able to find any more information about the liberation of Rudolf Abel/William Fisher or the fictional relative mentioned in the video. Any information would be absolutely awesome I have already used this information in a paper, and writing it got me more curious about it. Thanks in advance. Heres the link to the video https://youtu.be/CRGuf-yW17k
Rudolf Abel has been exchanged for the shot down U2 pilot Francis Powers at the Glienicke Bridge in Berlin. Yuri Drosdov was involved to make the deal happen and stay in contact with Abel in the meantime. For this he played the role of Abel's german cousin Jürgen Drews for having the legal oppotunity to contact Abel at all.
If you want to know more, there's a book, Whittell, Giles Bridge of Spies. Steven Spielberg made it into an eponymous film.