This could be very easily solved. Bootyhunter (Don't know your real name, sorry). Do you have the original pictures of the item sold? Fetts seem to have **** paint apps so it shouldn't be too hard to id some individual paint blemishes.
Yak_face needs to take a video of these loose limbs that clearly ids the Boba Fett as the sold one. Unless he has spent the past two months playing with the figure, the limbs should still be stiff as the seller states. If they are swinging like nuts under a dick on an august day then the buyer is probably right, although 5 weeks is a bit of a piss take. If you spend £75 on anything you check it when it arrives, surely.
Anyway, thats my suggestion. Good luck sorting this out.