I picked up an interesting C clamp today, on one side of the main casting it says GRAND DualGrip REG US PAT OFF, on the other side it says 40A and 40 (presumably casting numbers), and QUIKCET Pat Pend. max opening is 4 inches. The copper colored parts were probably nickle plated, I polished them and there is a little silver still visible.
to operate, squeeze, slide the clamp bar down, release (spring force pushes it together) and tighten the screw. to release, loosen screw and rotate clamp bar 90 deg to disengage ratchet.
I tried to post to the dropbox but it seems that the metalworking.com site is inoperative right now - and I always go there first to get the address du jour.
so meanwhile - anyone recognize it from the above description? I can't find anything on line about it, the company, or anything - the heavy copper plating with nickel suggests to me that it's probably pre WWII, but that's all I've got to go on
if you would like a photo, get my email from my web site (below) and send me a request and I'll send you the photo I was intending to put into the drop box