Autocar Glass Plate B276
It could be a Lagonda
Yes, a 2-litre Lagonda. Most frustrating that the photographer carefully took up position so that we can't see the competition numbers!
It could be W.G.Barlow who had raced Bentleys at Brooklands. It is definitely a Lagonda Two Litre High Chassis tourer and if it is "Geoff" Barlow it will be OT 9381 that he had just bought.