I have a RMSc mated to my Hellcat OSP. At the time I purchased my Hellcat, there were only two viable options for a ready-to-fit red dot option. At any rate, after a few years of use, I need to change out one of the screws that attaches the RMSc to the Hellcat, and I’m not sure of the way to identify it so I can purchase it locally. I’m sure it is probably a metric thread. Anyone have an idea of ident of the screw and possible places of purchase; I don’t want to source out of England. Thanks much.