I sold my first 6138 UFO to a local collector and now another UFO is sighted (dated July 1972). I just could not let this one pass as the condition is excellent although the minute hand is a little chipped off. The 6138 is a beautiful series, and since I already have a 6138 Panda, I thought maybe I should channel some energy (and funds) into this range. The other movement that I target to collect is some 6139.
This is how the 6138 UFO looked like in an early Seiko catalog (picture courtesy of another collector)