Bit left field, could you run a threadless BB? Cheap enough to try, most of them are on a JIS taper so no Campy cranks. Make sure you tighten them up with grease as this really lets you torque it up! Other options might be to skim the face of the BB by a mill each side and find an old BB as Sig has mentioned!
I use one similar to this which has given me no trouble for several years (as long as suitable torqued up)