1937-47 ½d green Watermark Upright, unique vertical Registration block of 20 with 22.5mm vertical gutter margin between two vertical columns of 10

Typewritten Registration Certificate on the reverse reading:

“This sheet of ½d. Unified Stamps, 240 set, for Endways Rolls was taken in the presence of the Post Office Control Officer at the factory of Messrs Harrison & Sons at High Wycombe for the registration of the first print of (such) King George VI stamps of this denomination.

(Signed) D.P. Dell
Senior Staff Officer.
20.10.37

(Initialled) JWH
Stores Department,
Stamp Section.”