I acquired this frame earlier this week. The previous owner has repainted it, but never got around to building it up.

There are no distinguishing marks to ID this frame, so I was hoping you all could help me find the make/model/year.

A few notes:

The seller told me the frame was Columbus SL, however he couldn't confirm this, as this was told to him by the individual he bought it from. Frame is relatively lightweight, but not "exotically" light (no guesses on a weight however, as I still have to remove the BB).

The dropouts say "Shimano SF".

The frame is drilled for nutted brakes.

It had braze-on shifter bosses and braze, top-tube cable guides (3 of them) and der. hanger. The shift cable routing went over the bottom bracket. (All the braze-ons were removed by the previous owner, but that's all right as I'm building this up as an around-town single speed).

There are no markings on the headset or BB.

The serial number is M1M55550.

The geometry is fairly slack and only has fender eyelets.


Any help would be much appreciated