Gray's Cal. Express, shield handstamp (Thomas GRA-100) on 1850 incoming cover to Sacramento City, red "New Britain, Ct., May 12" origin cds and manuscript "40" rate, with additional "Ex $2-" express rate notation, pencil "Sept 1st, 1850" docketing at bottom left; cover edge wear, otherwise Very Fine, a very rare Gray's California Express usage with only six examples recorded, ex Polland. Estimate  $400 - 600. $0 (Image)