Peter said: "The model with the dark red headtube was just below the Equipe and the only difference I think was that this had Weinmann 999 brakes rather than Campagnolo and mudguard eyelets."
I think this another data point, but not exclusive. Mine was definitely the top end model, sold to me as a 276--and it is/was all Campy including fork ends, seat tube and brakes.
And it had the flam red head tube! To confuse matters more, it was purchased summer 1971, and it already had the Cinelli crown and flattened stays!!
And the eyelets were definitely there on mine. (As had been said about other marques, in a lot of US racers ground those off, even though the British makers continued to use them on their high end bikes...)
AFAIK, the Weinmann (as with other makers) on Falcons were spec'd on the high end models until the Campy brakes were more generally available. I have seen examples of the earlier "San Remo" that have the rounded (not flattened) rear stays, flat fork crowns (not Cinelli) whose overall appearance seems to place them in the mid to late '60s (this is all from photos), with all Campy except the brakes --and these are Weinmann 999.
To confuse matters still more, it appears by the time of the catalog on Mark's site (and Robert Broderick)--(one has the 1973 and one the 1974?--are in fact page identical), and with the expansion of the "San Remo" name to include other models, they did continue to offer a San Remo that still shipped with the Weinmann brakes.
Add to that, Falcon sold bare frames, so dating from components is tricky. Probably the strangest to me was someone who emailed off the Sheldon Brown page asking for information-and theirs was all period-correct Zeus equipped.
Did it go out the factory door that way? Beats me--there is certainly not a model described with Zeus in the few catalog pages available, but in the boom era, anything was possible.
I tend to agree with Dale's comment (although my shop never stocked Falcon): "every box opened might have a new surprise... It was the norm to see trim & decal variances, parts variances and, most disturbing, sometimes seamed tubing and steerers on bikes (usually mid range) that sported Reynolds 531 decals." Reading the catalog pages don't tell you all that much about what they had on them when went out the door, and I think Falcon's model descriptions are cagier than most...
My "quest" started when I was planning on a restoration and could find very little information--that's what prompted the page that ended up on Sheldon's site.
For interested parties, there is also an ongoing thread on Roadbike review in the retro classic section that I have posted to that has some great photos and an ongoing discussion about Falcons. I still have plans to post a stand-alone page at some point, but other priorties have intervened.
Cheers,
Dean Kernan
Pomona, New York