Interesting frame with some familiar features. Italian BB. What do you think?

The fork is a Faggin, and the bottle cage bosses (which I didn't manage to get in shot) are large and round. Maybe addons? Paint is so thick that no serial number is visible...

Indeed, it's not the fork that is hard to identify

My guess would be Olmo of middle range quality, perhaps a Grand Prix...

I have a Raleigh Team Pro and an Argos with those same lugs. (Yours isn't either of those). They seem to have been relatively popular on nicer bicycles in the mid-late 70's.

I just noticed the Valero with the 980 steerer and 531 decals has the same lugs

The brazed on bottom bracket cable guides are I think from a clamp on unit cut apart... could be silver soldiered... hope they did not breath the chrome vapors...
Forged rear ends are brand X- not Campagnolo.
Seat stay tops are kind of basic, slit and fold.
While it is Italian threaded... check the shell width... tossing aside the fork, does not look especially Italian... things can get tapped oversize.
The frame I conjecture has seen post creation work. One has to be careful placing any not on those type of modifications to guide the maker.

BTW, when I was a starving student, and putting back into service a frame I had, I bought a 980 rear mech, Just could not buy Japanese on what was otherwise a full Campagnolo bike... well save for the Miche hubs, but they looked the part. Worked as well as a Nuovo Record unit.

dropouts look like they might be Zeus Gran Sport, check out Velobase. Not sure where that leads (if true) with an Italian BB...