SG 53a 1½d rosy mauve plate 1 1860
scan courtesy Mike Holt
The 1½d rosy mauve was first printed in 1860 because of a proposed change in postal rate, but the change was not approved until 1870. 10,000 sheets were printed, of these 1,000 were overprinted "Specimen" and distributed to postmasters. Of the remaining 9,000 sheets, 8,962 were destroyed in May, 1867. The remaining 38 sheets (9,120 stamps) have since been split up and are in the hands of collectors. Rikki C Hyde
Plate 1 was used in 1860, which does not have the plate number in the design. However the 2d plate 7 issued two years earlier in 1858 had the plate number incorporated into the design. The 1874 1½d plate 3 had the plate number incorporated into the design. The 1d had the plate number incorporated into the design in 1864.
For the issued stamp go here