'POSTED AT LONDON S.E. UNDER/COVER TO THE POSTMASTER OF DOVER' INSTRUCTIONAL HANDSTAMP. 1868 envelope apparently sent London to Birmingham with 1d plate 76 (SG 43) tied London numeral, backstamped London AU/5 and Birmingham AU/6 1868 with very fine strike of this instructional handstamp but originally posted at Dover to London within an outer cover for nefarious reasons. Rare. (Ref 52250).