Many thanks, Paul; this is all very helpful.

While I've not been able to tie him definitively to 41 Sqn, he is currently looking like the most suitable candidate.

His service no. indicates that he enlisted as an aircraft apprentice in Entry 22, Class 3J, 1 Apprent Wg, 1 STT, Halton, in Sep 1930. He appears to have graduated as a metal rigger in Jul 1933, but it was a rapid climb from A/C apprentice to u/t pilot within three years. Most men I have come across seem to have taken at least twice that long.