I’ve been trying, unsuccessfully, to identify this unlabeled steel frame. The paint scheme really looks familiar, but still hasn’t rung a bell.

Scalloped seat stay caps, cinelli bottom bracket shell, sloping fork crown, campagnolo front dropouts. shimano rear vertical dropouts. Fork blades appear ‘flattened’ (for aero?) close to the crown.

Components were a hodgepodge of super record and shimano 6400, can’t trust date codes there. Wheels were not part of the sale.

Seat pin is 27.2. Single set of bottle cage mounts, some kind of embedded bolts. Recessed brake mounts.

Paint appears to be of original quality. No trace of any decals. No numbers found so far.

Any help is much appreciated.

I don't know who built it, but it looks cleanly done. I suspect that the fork is not original to the frame: the stay/blade end treatments are different, as are the dropouts (front is Campagnolo, rear is Shimano UF).

Good catch on the stay/blade end treatments, thanks. The different dropout manufacturers was a big indicator, but this pretty much confirms the fork and frame didn’t start off together.

To identify the frame, we have cinelli BB shell and scalloped stay caps, old enough to lack bottle cage mounts on seat tube but new enough for TT cable guides and recessed rear brake mount.

Centurion was an adopter of vertical dropouts earlier than the other Japanese makes. Cinelli BB shell was not uncommon on early 80s Treks, but I’m thrown off by the scalloped seat stay caps.

It's not a Trek; Trek never used those lugs, seat stay ends like that, the square chainstay bridge, or tube-type under-the-bottom-bracket cable guides. The stud-type bottle cage mounts are likely an aftermarket modification.