TOC said:
From that one side-view, I cannot see the radiator shape, but I can see the side of the bonnet, which looks like it curves to a Humber shape. I find no 20's Sunbeams with low headlamps, either.
The Humber shape was multi-sided, and from the picture, though not head-on, you can see that the visible matrix part of the radiator has vertical sides and a horizontal top. Humbers don't. You can also see that the cowl (radiator cowl, not scuttle) has a curved top.
I agree Sunbeam is another choice, but that reminded me of yet another - it might well be an Alvis. It would be a 12/40, I think, because later ones have wire wheels.
How about this one?
It's frustrating not to be able to identify, as I once could, cars which were reasonably commonplace when I was a boy!