Why no comment on rethreading? OK, I'll make comments...

It's true that Italian threading has a larger inside diameter than all the other threadings. We would use Italian threads when we had a trashed bottom bracket. It's a decent revival technique.

But it requires expensive tools, and not many shops have them. Once you find someone able to do it, I don't know what he'll charge you. Ask around.

I didn't know Italian thread BB's are easy to find. Why is that? Is Italian threading still in common use?