Originally Posted by
Northorne
.....Also, is it possible to have it re-threaded to a standard size at a machine shop?
Anything is possible but the cost in this case would not justify the effort on such an old and outmoded frame that is not some highly sought after classic. If it does turn out that you have the proprietary BB threading then it's time to sigh and call it quits on this one and move on to a new project that uses a newer source of inspirational components.