It is a Soma Dura-Ace equipped model. Made in Japan in the mid to late 1970's I believe. I date it mostly by the component group. It is out fitted with an early generation Shimano Dura-Ace group. the black anodized group was first introduced in 1976 (that's the spirit!). The rear derailleur is a later year production because the first ones were still called Crane and had black anodized parts. I assume this was a nod to Campagnolo's Super Record group which was also in production at the time, and Shimano's main competition in the high end road market.
The frame is very well constructed. All the lugs are nicely thinned and the brazing is very clean. The paint is relatively thin and as so reveals imperfections quite easily. It has a very nice fully sloping Cinelli style fork crown. The tubing is unknown because of a lack of decal, but it is double butted and very light. I am guessing Ishiwata, perhaps, or maybe Tange Prestige? Soma made a full line of bikes in the 1970's and there is not a whole lot of info about them out there. I am guessing this was their top of the line offering due to the fine construction, classic styling and high end component group. The Dura-Ace decal on the down tube appears to be original from the factory as well as the others. Nice orange paint shimmers in the sun. Serial number stamped on seat tube by the BB shell is: 77 1636.
It currently is missing pedals. The rear wheel will need to be re-built because the rim has a couple cracks at the eyelets. Also, the brake levers are Suntour Superbe, not Dura-Ace. The measurements are as follows:
- 57CM CTC seat tube
- 55CM CTC top tube
- 33" stand over height
- Shimano Dura-Ace low flange 36 hole black anodized hubs laced to 700C Rigida eyeletted rims.
- Shimano Dura-Ace rear derailleur, black anodized (later model)
- Shimano Dura-Ace front derailleur, black anodized.
- Shimano Dura-Ace crank set 52-42 ring combo 170mm arms "B H" date code, black anodized.
- Shimano Dura-Ace bottom bracket.
- Shimano Dura-Ace brake calipers with original pads and wheel guides, black anodized.
- Shimano Dura-Ace head set, black anodized.
- Shimano Dura-Ace brake cable guides.
- SR bars and stem.
- Suntour Superbe brake levers with nice gum hoods.
- Vetta saddle with alloy pillar seat post.
- Shimano Dura-Ace clamp on shifters, black anodized.
- No pedals.