bikemanbob

I recently purchased this bike at a yard sale and have not been able to identify it. It has no identifiable markings except the serial number on the bottom bracket (M4J00615). The color is silver and it does not appear to be repainted. Where the paint has been chipped away, chrome is visible. It is a non indexed 12 speed with campy downtube levers. The brakes and drive train are Shimano 600. The wheels are 700's. The chain rings were made in France and the bottom bracket is Japanese. I have weighed the bike (as you see in the picture) and it weighs less than 24 lbs. If you have any ideas, I would greatly appreciate it. Thanks.

cyclodan

Frankenbike...but a very nice frankenbike.
Are those cranks Stonglight? Sugino?
What is the seat post diameter? That would be a clue to the tubeset and or country of origin. The frame looks like it was designed as a 700c wheeled bike rather than a conversion and has nice minimalistic lugs. A late 70's or early 80s high end production bike or maybe a custom handbuilt?
I'm gonna say probably a repaint if there is chrome underneath but no chrome stays or fork lowers left exposed.

bikemanbob

I posted more photographs. As the photos show, the cranks are sugino. I will get a measurement on the seat post tomorrow. The individual who sold the bike said that the the bike hung in his garage for ten years after a neighbor gave it to him (the neighbor was going through a divorce and he didn't want his wife to get it). The seller believed the bike to be european, but that is unlikely. I've been searching miyata catalogs for a likely match. Thanks for any input.