This looks like a Frankenframe to me! The head tube lugs look like long point Prugnat type S4 while the seat tube lug and seat stay tops look Italian.
My guess is that it was crashed and pieced together with a different front end. That could also account for the fork.
Back in the 70s ran across several Belgian bikes with Italian BBs including a Belgian made Bertin.
Chas. Colerich Oakland, CA USA
Norris Lockley wrote:
> Jody, I would be surprised if the frame is Italian, even though it has an
> Italian bracket thread.
> The fork crown was available in the UK from Ron Kiching, in his MILREMO
> range..I still have about ten of them left and use them from time to time to
> match up with Nervex Pro lugs as they go fairly well with a bit of filing
> and are far stronger than the Nervex pressed steel one. Check the fork
> section - is it the old thinner Imperial section of the Italian fatter oval?
> I have never seen one of these crowns on Italian oval..but they could exist.
> The top-eyes on this frame and much else look fairly English. At first
> glance I thought it was an early MKM..as they made quite a lot of frames for
> the States, some of them with Italian threads. Also some were shipped to
> Proteusand Victor (?)
> Hope that helps
> Norris Lockley
> Settle UK