school me on my olmo bottom bracket
 

Finally getting around to building up an olmo frame I purchased last summer. Was planning on building it up with some campy but I really want to ride it and don't have to cash to throw around for it. So I'm thinking of going with a more modern build with parts that I have, I want to use a shimano 105 group I have. My bottom bracket is 68 mm wide, so thinking english threading? I thought I had a couple that would work and the spindle length is right but they just slip inside of the shell, the threads touch but I can just push the cups inside. What do you think need to order? Thanks. Al.

sounds like even tho your shell may measure 68mm, it's Italian threading. you may need a shim for under the fixed cup to get chain-line right.

That's what I was thinking, but wasn't sure if they had shorter shells that were italian. so If i get a 70 italian thread and 2 mm of spacers I'd probably be ok?

probably just a 1mm spacer for under the fixed cup and let the adj. cut fall where it may. Doesn't hurt to have a selection of shims so you can try-and-err, they usual come in 0.5mm and 1mm thick, don't know if they make them in 36mm ID for Italian cups or not, but if you have to clip them to fit the larger diameter, they still will work as shims.
The shell may have been "aggressively" faced and somebody ground away that much steel, but could also have been re-tapped from BSC to Ital.