This is really getting good now! The subject frame has track dropouts to which a hanger has been welded.
(If that is brazing, shame on the brazer for not filing soft brass down any better.)
In the picture directly above my reply, the BB guides appear to be unpainted. In another shot above, the top tube cable guides also appear to be a different color than the frame tube.
I'm suspecting these were also later add-ons. Could this be an old Keirin frame brought over and converted?
I see a bushing between the seat tube and the seat post. If we knew the true inside diameter of the seat tube we could better appraise your tubing quality.