It has always been known that although there are two printers for the KGVI £1 Coronation series, thick paper (Ash), and thin paper (McCracken); there is also only one “SPECIMEN” £1 stamp. Well actually there are three £1 specimen stamps.
1. Blue-Black overprint (John Ash)
2. Grey overprint (John Ash)
3. Blue-Black overprint (W.C.G. McCracken)
Displayed is the blue-black and grey overprint of John Ash. And as yet, there is no available McCracken stamp that is in well centred and MUH condition. Both stamps are certified.
If purchasing a £1 Coronation stamps, they must be accompanied by a certificate of authentication.
Blue-Black on the left with deep blue shading, and Grey on the right with dull blue shading.