Originally Posted by
boneshaker78
Big discovery! While stripping the paint I found the down tube stamped Reynolds 531 Butted 20/23! That may help a bit, dunno... but helps me know what tubes I've got regardless.
and THAT's a big clue, pointing away from Japan and toward a 27.2 seatpost. Might be UK, but doesn't rule out some other locations including No. America.