Contra Costa County Postmark Collection. Approximately 480 covers and cards; most 20th century to modern, many better early postmarks with highlights including 1876 Clayton manuscript, 1883 Cornwall Station, 1902 Eastyard, Lafayette including early manuscript (dubious franking) & 1888 oval, 1884 Martinez Wells Fargo usage, 1894 Orinda Park, Pacheo including express, 1883 & 1894 San Ramon, 1888 Selby, 1890 Somersville, 1897 Tassajara & Walnut Creek; clear readable strikes throughout (no photo). Estimate  $750 - 1,000. $0