Falkland Is 1937 (25 Oct) Red/Buff Formula Registered Envelope (Perkins F1)

1937 (25th October) Red/Buff Formula Registered Envelope (Perkins Type F1) Franked by 1929-36 2d Grey and 1937 Coronation set of 3 tied by very fine strikes of Port Stanley type PSA2 CDS (and by New York Transit CDS) and used to Boston USA with Crown/Registered mark at lower left. New York and Boston (x2) Backstamps. Scarce and attractive. (with copy of Letter from Recipient to Postmaster Offering Congratulations for the Fine Service)