Very high glass area hints at a special vehicle. From a taxi concept to a Popemobile... But no clues I could get, so far...
Roof mounted rear indicators look very much like Citroen DS. If these barely seen lines on the trunk are air vents, then it may hint at rear engine like Tatra - but if it was a Tatra I should be able to recognize it. So my guess is that it might be based on Citroen DS.
Wheels are too small to be American but it looks as though it wants to be American. Is it British ? An Anglimp ?
I found it but I'm still a bit confused: Rootes-Chrysler.co.uk - covering Chrysler Europe, Rootes Group, and Talbot cars From this I suppose that this is original ERA produced rear-engine concept for BMC. It differs a lot from final Rootes Swallow prototype it was developed to... So BMC or early Rootes?
My understanding of the story is, like yours Dino, that this is the original prototype developed by ERA for BMC, which was later developed into the Swallow prototype for Rootes. Well done!
Well, a Deutsch-Bonnet, I suppose (from the name of the picture file....) ... I don't know which one exactly (there are several DBs that are quite similar), but someone else certainly will.
I'm pretty sure it hasn't been used in this thread yet. Sir, I'm afraid you have fallen for the lady's tricks, as this is no DB. For a hint, however, I suggest that you take note of the diminutive size and RHD configuration.
Cherryca Phenix made a beautiful 1/43 model of it back in 1960s, calling it Prince Sprint Coupe. Found it as Nissan Prince Sprint 1900, too. It has been made in 1963.