Hi Irene
I've had a chance to dig around and found a bit more - this from Flight, 29 October 1915:
Aviators' Certificates.—The granting of Aviators' Certificates Nos. 1820 to 1891 was confirmed.
The granting of the following Aviators' Certificates was confirmed:-
1917 2nd Lieut. Geoffrey Victor Randall (Maurice Farman Biplane,
Military School, Farnborough). Oct. 13th, 1915.
The link is
shoreham | 1915 | 0829 | Flight Archive
Happy hunting
Graeme