Lot 42121 – 1914-26 Waterlow Seahorse 12p on 10s indigo-blue with “SPECIMEN” ovpt (type GB23) in mint n.h. lower marginal block of 8

1914-26 Waterlow Seahorse 12p on 10s indigo-blue with “SPECIMEN” ovpt (type GB23) in mint n.h. lower marginal block of 8, from plate HV4 with proving centre-guide, with pencil “AM” initials in lower left corner and “L” at lower right, slight gum disturbance in lower margin and a little perf. separation in right corner, an important and spectacular positional multiple, unique in private hands (from the one sheet of 40 released); ex BPMA archives.

Note: The usual 10s UPU “SPECIMEN” ovpt is a different type (GB26).