I have some dual load style shot shell holders I built a while back. They use real delrin for the back plates. I can give some options in mounting. Many of them are set up for Molle-loks to go on webbing. A few are set up for Tel-lok. I can add more holes if necessary to make them work either way.
8 shell caddy w/ attachment $30
6 shell $25.
Whole vest as is with 2x8 with molle lok$65
Drop leg piece with 8 $35.
All negotiable on configurations, package pricing possible. The materials, time, and the clips are worth some $ so ill give a fair deal but not giving it all away.