Here are some photographs I took when I visited the Donington Park museum in October 1989.
It's a 1936 Alfa Romeo 8C-35, an ex-Scuderia Ferrari car, chassis #50013, that was owned by the late Dennis Poore from just after the war until he died in 1987. He competed regularly, and successfully, in the car in this green livery until 1955, after which it was put in storage until it was sold after his death.
The car then spent a few years in the Donington Park museum, but was subsequently sold to Peter Giddings who had the car fully restored in its original Scuderia Ferrari guise - and painted red, of course.
On 27 February 2016 I showed photographs I'd taken at the Coys International Historic Festival meeting at Silverstone in 1997 of an Alfa Romeo 8C-35, but I don't know if it's the same car.