Hi Davydo, welcome to BF, I am a former Botty rider from the 70's. Are you talking about a modern frameset or a vintage one? As Dudel said, the mechanics forum is a good place to start and if it is a vintage frame, the classic and Vintage Forum can guide you in how to determine the type of threading your Bottecchia's bottom bracket has, most likely either Italian or English. the people in either forum will be able to guide you about this, it isn't hard at all. Post your questions in the appropriate forum and get to know the members there.

Bill