Guess we only call it an N or an NC because thats what it is to us now, as it was never (imo) a production model. However i think the 74033 PVD is likely to have surfaced later than the 1974-6 range, perhaps closer to when Heuer became insolvent. Even possibly coming to the market in a simlar way to the 73633B re-dials (maybe in the 80s), albeit as genuine Heuer parts from a prototype that was never adopted due to the inconsistencies of the PVD process. Having owned quite a few of these i can say the the slightest wear (for instance 2 weeks of winding) can take away some of the PVD edge finish, not something i suspect that customers would have found acceptable. On the plus side the PVD finish looks and feels nicer than the variants that made it to full production like the Monza or Montreal, the Monacos has a smooth, silky finish the others are rougher.

All interesting stuff.

: The Monaco PVD predates the 1 indicating PVD being adopted. The key
: for that Monaco is in the suffix - NC for black case.

: At this point PVD is still something of an experiment. When we see
: it put into serial production on a barrel Carrera it has both
: the NC suffix and the 1 indicator (110.571 NC). Subsequent PVD
: watches, like the Montreal and Monzas, all use that 1 indicator.