Help me bend metal - Brake content

I've been looking for a decent deal on a sturdy metal brake for a while, and finally found one that seemed pretty solid on local CL. Definitely seems like a home-built piece, but it's really stout. I definitely need help on a few things

• There are two handles that clamp down to hold the work-piece in place, the red and green. The red handle doesn't actually "lock" into place like the green one does... Can it be replaced? Should I try to be adjusting something else? I don't think that I'm missing something, but I can't make a clean bend without that.

• Any suggestions on mounting it to a bench? Right now it's welded to a probably 40" long piece of big angle, 3 or 4". Not sustainable, and it wants to fall off my bench constantly. 

The smaller bends I've tried worked really well, so I'm excited to get this sorted and start building my floor patch panels. It's a 23" bending width, so I won't be doing anything too big, but still a good starting point. 

C clamp the angle to the bench

The clamps on that unit are made by destaco. The rod with two nuts on it is adjustable for pressure. If nothing is broken you can increase or decrease the clamping force by moving the threaded rod in or out

Handel is not suppose to lock. It I for safty. If you ever get a finger in one of those trust me you will understand. I ran a metal shop for a large roof in company and we had 8' and 10' versions of those things and they were very good at damaging fingers. Keeping one hand on the clamping lever at all times minimizes the problem. You also use it as leverage to pull on as you lift the other part to bend the metal. It keeps the torque on the brake down and keeps you from damaging the brake. On last thin you need to learn how to adjust the clamping force as well as the offset of the jaw for various thicknesses of metal.