The key to dating a Cinelli is the lugs (3 holes or no hole) and the bottom bracket oil port. The presence or absence of these features will help to establish the manufacturing date of a Cinelli frame. The BB port disappeared in about 1965. The 3 holes in the lugs appeared in about 1968. The Special Corsa ("A" model) is distinguished by its sloping fork crown, where the "B" model has a conventional flat fork crown.