If it's only a PPC accelerator why not just buy the efica itself?? Making that sort of hardware for the A1200 wouldn't bring any advantage over the efica board, plus making it expensive and just for a nitch of market.
I don't even see the point of having a PPC card on a Classic Amiga, the Sam cost's the same as a PPC card for the A1200, and it's new!!
If you want to upgrade a Classic Amiga go for a 060 card, a Blizzard if you can!
But that's just me...