stevef is spot on
Good eye.
The speed placard has been blurred to obscure the Chilton name, however the Carden Engine placard was not retouched. Yes, that is a choke control on the right, as the engine was a 32-hp cast-iron Ford auto engine with the Carden modification of dual magneto ignition. The Chilton was also the only design I know of that was built in the De Havilland factory but was never named a DH product.
Seen is a Coventry based DW.1, G-AESZ built in 1937. You have control.
