with respect to the pantographed chainring, at first sight it may appear to be same as the one we see on many colnago's and frequently by themselves on ebay, but it isn't. the "C" is bigger, and it is not "framed," by a thin groove, unlike the more common chainring. additionally, this ring has cutouts in between the spider arms. i'd never seen this ring before. i would guess that it is period correct to the bike, and is an early version of the more common pantographed ring.
ray dobbins
miami florida