87141 - 1857 STIRLING "308" ROLLER. A used block 1857 of 15 1857 die 2 1d rose-red on white paper

1857 STIRLING "308" ROLLER. A used block 1857 of 15 1857 die 2 1d rose-red on white paper lettered AJ-EL, some trimming of perfs and AK with damage but cancelled 3 fine CONTINUOUS  STRIKES OF THIS RARE ROLLER EXPERIMENTAL CANCELLATION, of which only 2 dated examples have been recorded. (Ref 87141).