This is the most objective history about this issue I've yet read (and I've read quite a few!). Thanks. I got a few new nuggets of information!

Is the situation you noted that only 13 of 27 members of the Supreme Soviet Presidium voting on the resolution in 1954 make any difference? Has Russia tried to claim that the return was not valid as only a minority approved? I have zero knowledge of USSR, Russian or Ukraine law, so I have no idea if that could be used as a legal basis for argument.