Wow, I really love this frame even if is not made by one of the most popular frame builder. On the contrary Bortolotto is almost unknown as a frame builder but has a good tradition in assembling bike and the brand is still working in their workshop nearby Rome.
But this was made by them, back in the eighties.
Bike has been built with ORIA tubing: PROFESSIONAL CROMO MOLIBDENO ML 25 ELABORAZIONE VETTA
More details on the tubing on the following links:here and here. This tube set is really nice, remids of the Gilco design used on Colnago Master with their star shaped section.
Here are some specs:
Seat tube 58 cm center to center
Top tube 58 cm center to center
Headset Campagnolo Pista
Bottom Bracket GPM
Of course this frame mounts 700c rear wheel and 650c front wheel.