Came across this thread while trying to confirm my reading of an entry in a diary that I have been researching.
The diary belonged to Dom Gervase Hobson Matthews and covers the period from 1 Sep 1939 to 31 May 1940.The relevant entry is as follows:-
"May 17. Friday.Had my photograph taken, by Phimister [???] (Ealing).Letter from Monica.Pon and I drove to Victoria after lunch, and I caught the 3.35 to Broadstairs.Located Gwyn with some difficulty; dined with him and to a flick."
The only word I was uncertain about was the "Phimister" - but your father being a photographer in Ealing from 1936 brings more certainty to the name being Phimister.