I do think that the OP's guess as to the era of the frame is probably not far off the mark. Normally, when I see Cinelli frame components, I'm inclined to believe that the person trying to ID the bike is jumping to conclusions based merely on fact that Cinelli frame parts were used. In this case, though, I'm strongly inclined to think that the presence of the "Flying C" stamped in the lower headlug means that the frame is in fact a Cinelli. (Or some type of show special intended to flaunt it's Cinelli connection.) The steatstay cluster, while not classic Cinelli, is a pretty common one for bikes "of a certain age."