The coach washers will work OK, but keep in mind they are usually stamped from sheet metal. This means that one edge might be nice
crisp & square, but the other may be slightly rounded, and this is the one that will burr your PAW slots. I don't know exactly how those
PAW guys put their backplates in, but they sure are tight. Hardware store washers are also usually made from mild steel, which can bend under heavy pressure, so I've made up a special PAW one from hard spring steel (large lawn mower blade) with sharp ground edges. BOB