Great Britain 1966 4d British birds (Ordinary) error, SG 696ad.
A superb unmounted mint, with full original gum, right hand marginal block of four with greenish yellow omitted and the Black Headed Gull showing an additional printing variety "HARRISO" omitted from position R. 15/5.
Offered with an example of the normal block for comparison purposes.
Pierron records only circa 30 mint blocks. This example is a unique block in this form.
GB Specialised Catalogue Numbers: W92/5d & W92j.
SG Catalogue Value £2,000+.
