Air Force List for May 1940 is online and ocr to be searchable at the National Library of Scotland.
Only two Samson listed
https://digital.nls.uk/british-milit...chive/96064822
77306 P/O E H M Samson is the closest match P/O serving in Admin and Special Duties Branch.
https://digital.nls.uk/british-milit...chive/96061402
Ross