It appears to be a specialty cornice brake. Cornice brakes used to be used for making "Ogee" gutters a long time ago, rarely used any more except for restorations. They were usually at least 8' long.
The piece you have looks like a bender made for a certain radius part of a short length that was probably a specialty part of some kind. It might be handy for making rocker panels.
I've been a tinner for 28 years and I've never seen a brake exactly like that one.
If you really want to know for sure post a pic over here:
http://www.thesheetmetalshop.com/forum/search.php?searchid=30824
I'm sure someone there has seen and maybe used one before.
