San Francisco, Cal. incoming from Boston, Mass. Large "4 " due handstamp (Blake & Davis 583) with cds dated April 4 & large "Paid" in grid handstamp cancelling 1851, 3¢ dull red pair, 1855 pencil docketing; slight cover soiling, otherwise Very Fine, this is pictured in Blake & Davis on page 108 and is the only copy known to them or us, a most important East-West rate cover as the rate had changed to 10¢ on April 1, 1855. Estimate  $200 - 300. $0 (Image)