Originally Posted by T-Mar

The Campagnolo dropouts are non-Portacatena, which would make it no earlier than circa 1984. Pinarello introduced their eponymous dropouts circa 1987. Consequently, it should be circa 1984-1986. The Treviso didn't have a brazed-on front derailleur hanger though 1985 but did in 1987. I'm not sure about 1986. In 1984-1985, there was a model called the Super Record Special which was basically a Treviso with a front derailleur braze-on.

The decals are an obvious replacement, as they are in too good condition and are incomplete. However, the paint appears to to original. In which case I'm surprised that the stay caps aren't chromed. Based on extant catalogues, both the Treviso and Super Record Special had chromed stay caps on 1985. Again I'm not sure about 1986, but they were gone on the Treviso by 1987.

It's also been suggested that there is only one set of bottle bosses. Is this true? The bottle mounts on the seat tube from this era can hard to see in side photos, as there is no raised boss, just a flush hole with threads.

It's obviously not a Montello and based on the dating aids, would appear to be mid-1980s, either a Treviso or Super Record Special. Of course, that assumes it's a USA market model. Variations are often seen on foreign models. You can raise your confidence in a Columbus SL tubeset by verifying that requires a 27.2mm seat post. Unfortunately, the OEM fork is gone, so the presence of a Columbus steerer tube can't be verified.