I have a fairly old mystery frame with an odd headset size. The headtube ID is 32.7mm and the fork's steer tube I.D is 21.1mm. It looks like a normal 1" threaded from a glance, but clearly isn't once you try putting a standard 30.0mm headset in the frame. Ideally I'd like to convert this frame to a threadless fork some kind. Probably an RST since they're the only ones left who actually make 1" threadless steerer tube forks. Any suggestions on finding the appropriate headset, if even possible?