Andy
ProClass has quite large diameter rear looptail tube and the rear drop-outs are wafer-thin. Also, the BB is usually machined but I had one once that wasn't
ProClass is also wafer-thin lighter compared to any other 'Goose, even a Supergoose
A USA Supergoose like the one I had at MK (with the dents, not this one I sold a few years ago
) will have the larger diameter rear looptail but the thickness of the rear drop-outs will give it away
Cali's and Experts are a bit trickier......
Calling Jonnygoose for a full explaination
Spen