They are NOT Bakelite - at least they failed the semi-chrome test. Most likely celluloid from that era? There are no seams - the material is translucent when held to the light. They measure 7/8 inch across and have a crude brass metal shank on the backside. I thought about using them to make a stacker pin then thought the better of it and will leave them as found.
Will arrive with tracking provided by USPO.