[mrmummert]

Check with sheetmetal shops or heating and air conditioning places and see
if they have an old one they might part with...Also check Craigs list.
The Chicago brake company (which is still in business) makes very good
ones. You can get either a full brake or a finger brake. (has adjustable
brake fingers) i'd suggest the later if you can find one.

I have one for our team (its a old 1940's Chicago full brake thats 6 feet long)
if i can ever get it out of the shipyard i work for. The sheetmetal shop here
decided to replace it with a newer one. It can probably bend 3/8 aluminum
with no problem. Its heavy as heck though.