His service record is held at the National Archives - ADM 188/847/100463:

Name Giles, Frederick
Official Number: J100463
Place of Birth: Reading, Berkshire
Date of Birth: 29 September 1905

http://discovery.nationalarchives.gov.uk/SearchUI/Details?ur...

I can't make out the name but it seems to end with "ignable".

Regards

Stephen