1870, Sc 7 – DIFFERENT PLATES – USED. PLATES: 4; 3; 11; 12; 13; 14; 8; 19; 20; 6; 1; 10; 12? Obtaining Certificates of Authenticity. Stamps generic certificates from The Philatelic Foundation, PSE, or the APS are accepted. NOTE “graded” certificates or “encased” items are not accepted. We accept combined order in 48 hours only. _gsrx_vers_1649 GS 9.7.2 (1649).