At first I thought it may be Standard Vanguard variant (because of the shape of the fenders and the V windscreen, but then I remembrered the Jowett Javelin had a similar look) so I googled Jowett prototype and found it from there I think.
I am old enough to have seen Jowetts on the street when I lived in England in the early 60's as a kid (they were old bangers then)
BTW I am a retired car designer, so I look at shapes and anylise them out of habit.
If you think I am a cheating , dont bother to give me the point, I just like remembering the cars and finding out about the ones I dont know.