I think checking for what kind of brakes the frames were built for is your best option. Campagnolo brakes had a clearance of 47 to 57mm when they came out in 68 or so (going by memory so don't quote me). About 10 years later they came out with a short reach brake version around 40 to 50mm. The Asian brakes were 39/49. So of course short reach brakes can't handle as wide a tire as regular reach brakes can do. So look for racing bikes designed for original Campy side pull brakes with a reach of 47 to 57mm and you should be golden.