blue handstamp (COP-100a) on cover to Marysville, California, manuscript "Berkshire O June 25" postmark and matching "Paid 10" rate, "Rec'd Aug 5th/55" docketing on reverse, very fine and rare, just 12 examples of this handstamp are recorded, 10 of which are outbound uses in red ink, and just two of which (this and one other) are inbound uses in blue ink