I was contacted in September 2013 by Dave Allanson who said that he was researching his grandfather's cousin, Wilfred George Allanson, who was in No. 7 Squadron RFC. He believes that Wilfred Allanson is seated at the bottom left of this photo. He supplied the following additional information:-
I made a search through Peter Wilson's Diary for mentions of Allanson, with the following results:-
Peter Facey, Winchester, England
20130926 originated