Left - Continental rubber Works, Erie PA. USA - numbers on dome and back. - Second W.U.Tel.CO. Pat 2.218.497 on back Continental Rubber Works U.S.A. - Middle Continental Rubber Works U.S.A. on back Pat 2218497 Pat 2304483 - 4th W.U. Tel. Co. Pat 2218497 On back Continental Rubber Works .U.S.A. Right - No embossing. I'm asking $15 for the group plus actual postage.