I removed a very odd bb today. It doesn't thread into the bb shell on the frame at all, simply relying on the threading on the bb itself. Therefore the bb shell is thread-less and smooth. Is it possible to fit a thread-less bb for this shell then? Is this the best way to go or should I stick to the old bb, cleaned and serviced of course? I would have to locate some new bearings for old one and if I could fit a new one without breaking the bank it would be preferable.

Note this thread on another forum has the exact same bb as mine.