Reading alignbore stamping on engine cases...?

Ok, I'm looking to purchase and engine case. It's step cut for 94mm. Just what I want, but the oil cooler boss is stamped 050. The seller states align bore is .050. I can't find .050 main bearing anywhere!! Am I looking for the wrong size? I have about 1.5 hours left before my opporitunity to own this gem ends. Is this case junk as a 1914cc beater engine? It's an AB case too.. so I believe a 1300 euro, or could also be made into a 1600cc. The main question is does the AB case also accept a 69mm crank? and standard 1600cc type camshaft? Any help, thanks.