1823 DORSET/"DORCHESTER 123" CIRCULAR MILEAGE MARK (DT225). Letter Cerne Abbas to London dated 12th April 1823, charged "10", altered to "1/8" and confirmed by CROWN style inspector's mark, on reverse fine to very fine strike (over flap) DORCHESTER/123 circular mileage mark with circles dated AP 12 1823 (DT225). (Ref 111691).