"San Francisco (Model Post Office Sta.) Cal., Registered, Nov 30 1915", two strikes of purple backstamps on registered Department of Official Coins and Medals corner card cover to Sacramento Cal., bearing 2¢ carmine, 10¢ orange (402, 400A), each with "PPIECo" perfin, 10¢ nat. s.e. at right, tied by two strikes of "San Francisco Cal., Model Post Office" double-oval (SF15-05), magenta "Return Receipt Requested" straightline and matching "Registered No." framed handstamp with pencil "970", Sacramento (12.1) arrival backstamp, Very Fine. Bomar Nos. SF15-06  Estimate $400 - 600. $0 (Image)