Panama California Exposition San Diego, Cal Entire Year 1915. Allover illustrated picture of fairgrounds and San Diego Harbor on back of cover from City Clerk San Diego, Cal. with fancy Exposition emblem to Azusa, Cal., 2c carmine canceled with San Diego, Cal. "Panama-California Exposition San Diego 1915" slogan machine cancel, Very Fine. Scott No. 406  Estimate $100 - 150. $0 (Image)