Thanks again JSH- I wasn't expecting otherwise but just as well to check.. Your information and that of DSH upthread suggests that Gios might've been ahead of the curve with this return-to-braze-ons business..
I wonder if anyone else around here has a 1980 (or even '79?) frame with original braze-on gear bosses?
Fwiw, I took roadking's retort to you to heart, and ventured to the central library to check out their 'cycling' section. Two unsurprising observations: 1)Most pictures of competitive cycling are not optimised for the recognition of the minutiae of bike design. 2) Predictably, within the illustrated 'historically' oriented books, no shortage of pictures of Merckx in either Faema or Molteni garb. In any picture from the Faema period which allowed discrimination, all bottle cages were band-on. A result which was to be expected- I'd guess even by roadking?
Anyway, photographic evidence for the existence of double brazed-on bottle cage bosses within the 1969-70 peloton (or in all likelihood some minutes in front of it..

) is duly noted as being sourceable within one of the two aforementioned French publications.
Until my question about '70s Campag. Record brakes is answered I'm going to go with my gut feeling that standard drop was 47-57mm and piccolo drop was 42-52mm, even though that means that standard drop would have been slightly too deep for my 1975 frame, which doesn't seem credible, but there you go...