AW: Helfen Sie, Fahrrad zu identifizierenen
Bought the frame off a guy who purchased it in Germany, so was thinking that it might be a good place to start. Outside of the 'unique' drill outs on the dropouts, there are no discerning markings. The fork seems to be quite 30's or 40's, but the windowed lugs are *probably* much newer .
Isn't it a Colnago? Have to ask as I'm not familiar with all this italian makers as I do not like their style- much chrome, less innovation. In fact I only love the frames of Dario Pegoretti as his work is finest machining integrated into the spirit of Punk.
I'm lucky owner of several frames that never will be identified and it's okay for me as the quality of an frame doesn't change, if you know the builder. As others mentioned, it is possible that you will never find out who did the craftmanship but i wouldn't spend much attention. It is just important if you want to sell it and I hope that isn't what you are going to do.
The frame is a beauty, so, If asked, i would say, remove the wrong decals and let this one just be, whatever it is. It's nice, it's cool- nothing more to know about. Probably (Bonanzero pointed it out) is this not an specific model of an known company but an unique custom made one- the kind of bicycle I always prefer because nothing is as rare as an handmade single piece.
The disadvantage of this bikes is, that most collectors are not very interested as it isn't possible to tell others "Hey I got an Masi!" (Herse, Singer, 3Rensho...) to get admiration but the real classicist will look and see if a bike is of value or not, whatever name is painted on. So care an pap on it.
Aside from this there is an mailinglist for collectors at
http://www.phred.org/mailman/listinfo/classicrendezvous Guess you should read the list rules before joining. Good Luck.