1937-47 1d scarlet Watermark Upright, unique vertical Registration block of 20 with 22.5mm vertical gutter margin between two columns of 10

Typewritten Registration Certificate on the reverse reading:

“This sheet of 1d. Unified Stamps, 240 sets, was taken in the presence of the Post Office Control Officer at the factory of Messrs. Harrison & Sons, Ltd. at High Wycombe for the registration of the first print of King George VI stamps of this denomination for Endways Rolls.

(Signed) D.P. Dell
Senior Staff Officer
22 September, 1937.

(Initialled) JWH
Stores Department,
Stamp Section.”