1856 MOURNING ENVELOPE SUNBURY TO KNIGHTSBRIDGE/PL.37(SG29)(JK). Fine mourning envelope Sunbury to Knightsbridge with very fine die 2 1d pl.37 in a nice red-brown shade on blue paper (SG29) lettered JK tied London numeral. On reverse good strike "Sunbury" straight line receivers hand stamp in blue and back stamped 10 JY 1856. Fine usage. (Ref 87935).