the one clue that jumps out is the 27.2 seat post. IMLE (in my limited experience) most Tange-tubed frames use a smaller post (mainly 27.0 or 26.8), ditto for Ishiwata 022 (usually 27.0) and Columbus Cromor.
Odd that a frame with internal cable routing, all-chrome fork and nice-looking lugs would be Exage equipped...and I see that the frame has eyelets on the DOs where the fork does not.