The Vx derailleur and Super Maxy crankset place this very late 1970s, possibly very early 1980s. Components in conjunction with a high tensile frame put this upper entry level, borderline mid-range. Most of therse frames were built by Kuwahara and have an open format serial number on the non-drive side of the seat tube, just below the derailleur. Please post what you find for my database. TIA.