Because of the year involved I'm asking this here instead of the Mechanics Forum. I have an Italian frame that I'm building up with a Superbe Pro BB and a 1985 Superbe Pro front derailleur. I mount a Sugino 75 crank on it and even after being tightened down the front derailleur won't adjust over far enough to throw the chain to the larger 53t chainwheel. Thinking the Sugino is different then the Superbe Pro crankset I then throw a Superbe Pro crank on it and it mounts up the same way. I check the Italian BB spindle against an English Superbe Pro spindle and they are identically 112mm and there is no offset in the spindle so it can't be reversed by accident. With the cranks mounted I check the distance or gap between the chainrings and the chainstay thinking the crank isn't seating correctly or all the way on, I check this against another Italian frame I have with Campy on it and the distance or gap is the exact same. What I'm thinking is the 1985 Superbe Pro front derailleur wasn't made for this large of a throw. I know some previous Superbe Pro BB's were 109mm but even giving the crank another 1.5mm in would still probably not work. Have any of you had problems putting a 1985 era Superbe Pro front derailleur on an Italian frame and not getting the adjustment or throw needed.

At some point, the SSP and Sprint BB tapers were specific to them. There were notes that these would not work with Cyclone and lesser Suntour cranks. I wonder if this might be part of your problem.

I just put a 1987 SSP front derailleur on it and it works fine. It appears that if you use a 1985 or earlier SSP front derailleur then you need to use a 109mm BB and if you use a 1987 or later SSP front derailleur then either a 109mm or 112 mm BB will work. You can easily see by the angle of the arm on the front derailleur that the 1987 has a lot more travel to it.

out of curiosity; what is the chainline measuring in front as you have it set up ?

it might help to nail down your problem.. (edit: ok i guess you did already !)
sheldon's bb page lists the later superbe pro crankset as having a 43.5mm chainline on 111mm spindle

and to further confuse things: on one italian frame i am running a later superbe pro fd with earlier superbe pro cranks on a 112mm campy spindle (everything is mismatched !) and it still works fine