Hi, i am building up what I believe to be a 60s Torpado Frame (pic below) and doing the necessary cottered crank to cotterless upgrade. I was going to build in a Campagnolo Veloce BB, the sealed type. I think the frame is threaded ITA as both original cups are right handed and they thread in fine. Pitch gauge says 24TPI too. But the new Campy BB is practically impossible to thread in. I got it partially in by working the BB back and forth (with the right tool of course), but without significant force it won't go much more. I suspect something isn't right. Out of curiosity I checked with some french cups and they are too small, so I guess it has to be italian right?

Before I bring the frame to the LBS to have the BB shell threads cleaned up, I was wondering if there were any other standard which could have been used by Torpado in the 60s (or 70s). Any experts out there know anything I'm not aware of? any tricks to getting the cartridge BB installed correctly would be appreciated!

thanks!