This Campy seat post is on a 1958-1959 Legnano Roma with the narrow rail Brooks B17 Campagnolo Model saddle. The groove in the tail of the seat pin is interesting. Not sure if it continues around the to the top of the pin or what purpose it served?
Also for reference, the first Campagnolo seat post (c.1956) with a steel pin, predating the release of the all aluminum version in 1958.
