1D ARCHER PL.99 EXPERIMENTAL PERFORATION ON COVER (RI) (SG16b). 1854 wrapper London to Glasgow with a very fine 1d Archer Experimental pl.99 lettered RI cancelled London "6" inland office numeral with London date stamp 3 JU 1854 and GLASGOW JUN 4 1854. Fine usage with cancellation clear of Alphabet 1 check letters. (Ref 100528).