San Francisco, Cal./Model Post Office. Oval cancels (Bomar SF15-05) tying 8¢ Washington-Franklin + Pan-Pacific 1¢ + 5¢ perf 10 on registered cover used locally, backstamped with two strikes of violet "San Francisco (Model Post Office Sta.) Cal./Mar. 3, 1916/Registered" double circle handstamp (Bomar SF15-06), cover with "Panama-Pacific International Exposition" corner card with magenta straight line handstamp "Commandant Exposition Guard", 8¢ Washington-Franklin with perfins "PPI Eco" (Panama-Pacific International Exposition Co.), cover was undeliverable with "Unclaimed" straight line handstamp & "Return to Writer" pointing handstamp, cover with violet Model Post Office Registry handstamp dated "Mar. 9" applied upon the return, some cover wrinkles, Very Fine, a wonderful usage. Estimate  $300 - 400. The Exposition Guards served as a para-military police force for the Exposition. Members had to be ex-military servicemen with exemplary records, and were organized into companies and platoons just like the Army. Their commandant was an active duty Army Captain. Many of the Guards were transients, and took the job for the duration of, or just part of, the Exposition. The covers sent out in March 1916 often were addressed to hotels, rooming houses, General Delivery, the YMCA, or other such addresses frequented by transients. Only one registered Exposition Guard cover has been recorded that was properly delivered to the intended recipient. The covers contained a bronze medal and ribbon awarded for service as an Exposition Guard. $0 (Image)

San Francisco, Cal./Model Post Office. Unusually clear oval cancel (Bomar SF15-05) tying 2¢ Pan-Pacific, Perf 12 on cover to New York, cover with lovely multicolor printed Patriotic design with magenta Expo. label affixed, Extremely Fine and choice. Estimate  $150 - 200. $0 (Image)

San Francisco, Cal./Model Post Office. Oval cancels (Bomar SF15-05) tying 4¢ Washington-Franklin + Pan-Pacific 10¢ orange, perf 12 + 2¢ perf 10 on registered cover to New York, backstamped with two strikes of violet "San Francisco (Model Post Office Sta.) Cal./Aug. 18, 1915/Registered" double circle handstamp (Bomar SF15-06), cover with "Department of Official Coins and Medals Service Building" corner card and adhesives with perfins "PPI ECo" (Panama-Pacific International Exposition Co.), some light cover wrinkles, Very Fine and rare, these covers were used to deliver Pan-Pacific Commemorative Coins. Estimate  $400 - 600. $0 (Image)