Well found Walkie!
So it looks like these Droids Fetts were released on at least 2 different card backs and who knows if there's a third being China. I'm guessing the most common is the Taiwan as there seems to be the most versions of this card back out there and I'm wondering if all the Droids Fetts came with the V5 blaster, maybe, maybe not. I'd still say that the V5 blaster is the least common of the general Fett blasters out there and who knows if there are both black and grey/black versions or maybe it's just a slightly different batch of plastic that was used in different factories (or maybe even the same factory). It's still a slight mystery as to what happened in the end to the final run of Boba Fett on the vintage Kenner cards but that V5 blaster does seem to turn up mainly on the Droids card back so I'd put that Blaster with a Taiwan Fett if I ever came across an opened bubble version of the Droids card back (very doubtful I ever will though).
All interesting to read about and a big thanks to everyone who helped out on this thread, maybe there's still some more info to come?