Great find! A fairly rare bike, and at one point apparently a pretty hot one. One guy (a BF member as it turned out) in California was looking for one on CL for a few years, apparently his 'grail' since high school.
Indeed I do have one that is all OEM but for the tires and some grease, bearings and cables, and even the tires were original when I got it. I bought it almost exactly 3 years ago, with some much appreciated coaching from Robbie.
Beautiful bike, ain't it?
The brakes are Dia Compe 400s in a rare bronze anodizing (maybe only for this bike??) , which is sorta but not really a match for the darker bronze Suzue hubs and Araya rims. I have seen the bronze brake set on eBay, quite expensive.
Crankset is Sugino Aero Mighty, pedals Suntour Superbe (surely made by MKS) with Christophe clips but straps spelling out 'Mikashima.' Some of them have chainrings that are anodized; mine and yours do not.
Drivetrain is Suntour Superbe/Superbe Pro...I think the last variant of a Superbe Pro friction-only RD? I don't have a good shot of the shifters.
Original saddle is the 'Hinault' Turbo, essentially the same as what you have I think.
Robbie is right about the headset, mine had chewed up marks on the nut from someone trying to adjust it without the proper wrench; it was 'indexing' and apparently that owner was frustrated. Replacing the retained bearings with loose balls fixed that pretty well, at any rate it has not recurred. Mine is a Tange Falcon but no reason to think it's not original.
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