Originally Posted by
repechage
For an age clue, I would search around for other model B's with that fork crown, there appear to be a few used for them over time. This one is one of the less graceful ones, but I think original, the bike appears to look and sit correct from the side view. I'm less sure about the paint, I would expect some evidence of the original graphics, somewhere.
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A bit tricky to find an exact match with the cranks, lugs, headset and fork crown.
Here are some close ones:
Cinelli Model B 1955 - speedbicycles.com
Cinelli Only: Cinelli Model B, Circa 1956-1960
Maybe I will change my advice for a RD from Campagnolo Gran Sport to Huret Tour de France