Great Britain 1840 1d black, plate 1b, SG2The finer of the two known Penny Black blocks that feature this rare cancellation cover Great Britain 1840 1d black, plate 1b used block of four, SG2. A superb quality block of four penny blacks with full margins, lettered "IA JB" showing non coincident re entry with portions of the original impression on "IB" and constant printing variety at top right of "JB". Crease through lower pair which in no way detracts from the wonderful appearance. All