Hi List, In response to the Japanese vintage lightweight question I believe the bicycle frame at Proteus Bicycles qualifies.I had my eye on this frame for a couple years and have decided it is too small for me.Mr. Yamaguchi said he could verify if the frame is one of his frames if given a serial number.He has a list of all frames he built including the ones at Proteus Bicycles when he first came to the USA.No relation to seller just one LBS,how could use the business.$600.00 was the last price Mr. Larry Dean quoted me for the Yamaguchi frame (no fork) with just primer paint and no decals or headbadge.Hope this helps a list members search of the Holy Grail( a NOS frameset).Yours truly, Martin Walsh in Vienna,Va