I have some that I made from orange Hi-Viz vest material and polyester casting resin.
It's about 4mm thick and I have 4 pieces approx 23mm x 105mm.
I want to keep one set, but you can have the other pair for $5 to cover the cost of postage if it suits your need. I'm pretty sure I can get them through at letter rate taped to a piece of cardboard.
PM me if you're interested.
Here's a pic of the recruit I did in it, along with a comrade in arms wearing green canvas micarta.
I have left both in a coarse sanded finish intending to emphasize the grip, but they will sand up to a smoother finish with finer grit paper.