Your best best is to source them from Mile High if you only need a couple. I think the real roll pins are from Spirol and you can only order in bulk.
They are heavy duty SS coil spring pins. Either metric 8mm dia X 32mm length, or SAE 5/16” dia X 1.25” length.
You can find similar pins from McMaster, but I don’t believe they’re SS and will end up rusting on you.
Sam