This is another proof-of-concept. The "full-sized" version will have screws from woodworking parallel clamps. These bolts rack the jaw pretty badly unless they're kept even, but clamps solidly.
I used U-channel because I had it. Square or rectangle tubing would be better. I'd originally planned to make handle extensions, but I found that using a stub of BMX seatpost worked well enough.
I used it on the bandsaw gear repair.