I saw a picture of Jon Williams' vise version and thought I need to mimic that.
I had one made utilizing a old pair of vise grips but my whimpy engineer hand did very little deforming of metal to pain ratio. I asked Jon for some pics of his so I could see if I could build one. Thanks Jon.
Finished last night after dorking around with the design and what metal I hand on hand and the old visegrip decommissioned.

Nice, Dennis!

I like how it replaces the jaws.

I'm going to have to copy that.

John