Allen, I think I understand what you've built but some close up pics of the stand with a part being held would really be helpful. I'm always interested in stuff like this. I use one of these mounted to a 2x6.
http://www.harborfreight.com/2-3-4-quarter-inch-articulated-vacuum-vise-3311.html
I've got another gadget I use that has 4 arms, made of thick wire with alligator clip on the end. I use some as well. Can't remember where I bought it though.