Proof Block Larger Than four 5c 1871 Proprietary, plate proof on India (RB5P3), bottom imprint and double plate no. block of ten, also 4c and 6c bottom imprint and double plate no. strips of five and 5c, 6c and 10c 'patent' imprint strips of three or four, usual light staining and small faults, otherwise fine-very fine, Scott retail as single proofs $660.00 est.