As you probalby know SPG is the Society for the Propogation of the Gospel, think it was actually formed in 1702. Papers relating to the Society are in the Bodlian Library and the Lambeth Palace Archive may hve some information

Initially all coils were made up from sheet stamps, joined by hand. Grover made a Gumming Table (for making up sheets of stamps into reels) and also Slitting and Reeling machines, to assist. From 1913, Somerset House experimented with continuous printing but it was not until the early 1920s that the...

Apologies - the file number I quoted is no longer valid. I have now checked and can confirm this file is 52/989

For anyone interested, the file number in the NPM is 52/782. I have not looked a the file, so do not know just what is contained in it.

The British Philatelist reference is in Volume 30 page 31 of June 1937. However the illustration is purely to prove the existance of Cyl 2, which had previously been unrecorded. There is no reference to it being an 'abnormal'. Perhaps a visit to the National Postal Museum might prove worthwhile - th...