OK - to the challenge................ this is a very tenuous trail..............
Looks like a civil Avro504K to me - only 300 on the register so....
last letter of the Reg looks like it's a L - if so (Very big IF) we have
G -EAWL - which seems to have operated for the Welsh Aviation Co out of Neath - can't find a single picture of the company or the old airfield,
EAUL & EAOL were owned by Vickers and I doubt they have had a big AVRO sign on the side
same goes for those owned by Handley Page G-EATL & EASL,
sort of leaves G-EALL that operated out of Northolt & Shoreham for Central Aircraft Co as a trainer
The hangars in the challenge look a bit more Northolt than Shoreham to me