Hi CarNut. Some more proof using a variety of real and inferred data. I modelled part of Oxford Street using an old OS map as the layout has changed a lot over the last 50 plus years.
Also, the car works in the real world and is not as massive a departure from the standard car as you would believe. Engine fits (scanned an original car to prove), just. Most of the upper structure including hinges, apart from boot would use the existing chassis. Please also look at where the roof meets the lower car body. There is little if any radius. I reckon the roof could have been bolted on or such like.
Please keep firing questions. I have studied this picture for three plus years and started from a completely different view. Thought thirties special based on where I wrongly thought the driver was sitting.
Am 100% correct on this, but have so far succeeded in only convincing one friend (who may have been being kind) that the car is an Alpine. Will keep going, which tragically for me involves mocking up the wrong answers, until the weight of evidence is so great the whole thing becomes like the last scene of 12 Angry Men (dressed up as an internet army).