Can you help to identify these frames, bikes or parts?

It's a San Cristobal. Before the hour record (51.151) models came out. Actually more '78.
From the look of it (decal and panto) it looks like a Columbus SL model.

I saw those shallow chromed seat stays somewhere, can't recall where.

Here a catalog from 81-83 (albeit the shallow seat stays I think, from my own searching, is from before the 80s, more late 70s):

https://docs.google.com/file/d/0B41COrvE5iuAOEdpbGQydlRzbWM/edit?usp=sharing

(courtesy of: http://www.raggidistoria.com/p/libreria.html)

PS: actually the "San Cristobal" is not a model per se. But with so many details I still haven't figure out a way to date them. Same have FM pantographed on the fork crowns, some the full F.Moser (curved script), some have shallow seat stays heads (?), some flat, some chromed, some have a full chromed forks, some only the crown, some have FM on the lower side of the BB shell, some don't, the seat stay bridge also changes a lot as the pantograph on the top lugs (you've got an M, I got a hearth), some got F.Moser on the dropouts, some don't, some got standard Campagnolo or Gipiemme. It is such a mix ...

Only certain thing is that they all were made from 1978 to 1984 (i.e. after he won in San Cristobal and before he made the hour record)

PS: just saw another San Cristobal from the 78 and it also sported the same shallow seat stays crowns, the FM on the fork crown shoulders and the M on the lugs. So I confirm your model is from 78-80/1 (from the 81 to 83 the catalogue models shows different details)