Thanks to Fred Hammer for breaking his own "no shipping to outside of the US" rule, I now have parts 5 & 6 of the XClaim! puzzle.
XClaim! number 5 is the F.U.s 'My America' LP. Otherwise known as "the one with the weird cover". Or "the one with the cover that isn't quite wide enough so that when you put the record in a little bit of the dust sleeve sticks out of the side":
XClaim! number 6 is the Jerry's Kids 'Is This My World?' LP, which is debatably the best of the XClaim! releases:
Numbers 2 & 3 still elude me... but hopefully not for much longer.