Hi Paxboy. That's not an Airspeed Envoy, first thought was it's a retractable or at least a trouserless version of the Percival Q6 but the glazing doesn't look right. Certainly looks like Gipsy engines of one type or another.
Trying to fit it to Croydon as well. Shadows suggest early morning looking SW or late evening looking NE - background hills look rather rural for the surrounding area in the 1930s. Bit in front of the nose might be Croham Hurst looking ENE from the aerodrome but, as I know from regular walks, the Hurst slopes quite steeply! Just a thought - might it be Shoreham, looking NE towards Truleigh Hill, houses on the other side of the River Adur?
Edit: It's the
Miles M.8 Peregrine!