1788 SURREY/'18 KINGSTON ON THAM' FIRST TYPE MILEAGE MARK (SY448) . Letter from Ham to 'John Spottiswoode Esqr Sackville Street Piccadilly' with fair strike of the very scarce "18 KINGSTON ON THAM" first type mileage mark in black (SY448) - filing fold affects, on reverse London date stamp JA 21 88. (Ref 70003).