I know jbholio will have the answer, but how frequently do Sachen carts have one game on the label but an entirely different game on the board? For instance, I've got a cart with Auto-Upturn on the label and Happy Pairs boots up. Oh, and I've also got one with Incantation on the label but Papillon boots...
I have about 60 Sachen games (about 40 NES and 20 famicom) and 2 of my NES games have mismatched labels. I think I have a Galactic Crusader in a Colorful Dragon cart and a Galactic Crusader in a Dancing Blocks cart. Sachen didn't have quality inspection of their games because of this and some of the games Nes.god bought from them about 5 years ago didn't work and they were new.