A small green one from Allan L: Cowell & Watson Lea-Francis

[Carnut]

I think we'll call that solved: the car is a Lea-Francis special sports made by (Bob) Cowell and (Gordon) Watson in 1946 or 1947 on a shortened chassis which was of the beam front axle type then current for the saloons. The story is that the body shape was designed by Denis Jenkinson.

This was chassis No. C442 and I've read that it was actually built by Leacroft Sheet Metal Works of Egham for Cowell and Watson; they were of course partners in the that company!  The article also says the body was designed by Dennis (sic) Jenkinson.

[Allan L]

Yes, according to our records it is chassis 442 and the other one we know of is 1618 - i.e. 588 cars later because chassis only used even numbers. Chassis numbers have no "C" despite what you can find online.
As I wrote, DSJ was credited with the body shape. I had an article from "Motor" or "Autocar" about C&W and the car which I can't easily find but must be somewhere.