I've had a look through my BR photos but cab shots are a bit thin on the ground.
A Brit cab this looks to be early days as it has no AWS fittings, also no blow down valve, but it has the fitting for it,
A Crosti (is that spelt right?) 9F on building, no AWS but it does have the blow down valve, No9
70051 in the 1950s not sure about the AWS, but you can make out the blow down valve in the far cab window,
92220 in preservation, it looks like it has steam heat fitted, in another photo it looks like it has the old G.W.R. ATC fitted. More important it has a blow down valve fitted,
OzzyO.