I can't offer metal dustwashers at present but I can offer 3mm acrylic dustwashers in a variety of colours:
Solid Colours:Translucent Colours:Mirrored:They are template routed, 3.2mm beveled and polished up to a high gloss shine with emery and Novus. They can be made to any I/D and O/D (inner and out diameter).
Price will be approx $6 each + shipping.
I'm also going to be offering 3mm thick button bezels shortly out of the same materials, similar to this (ignore the pink, it was just for practising):
The bezels will also come with a drilling template accurate to within 0.004" of the slagcoin layouts to enable you to drill holes in the CP so that the bezels line up with the drilled holes. The drilling templates will be available with 1 1/8", 28mm or 30mm holes depending on what buttons and drill bits you are using.
I'm just finishing off my dual router table so I can get on with them, I should have it operational enough to start these in the next few days. LMK if you are interested and I can add you to the list.