I took this photograph at the Donington Park museum in May 1989.
The board in front of the car says 'OSCA', but perhaps it should say 'OSCA-Maserati'. It's the Maserati 4CLT/48 of Prince Birabongse (better known as Bira) which had been fitted with a 4½ litre V12 OSCA engine for the last race of the 1951 World Championship season. The works OSCA 4500G used the same engine and had a similar appearance to this car. Bira's car (and the OSCA 4500G) became obsolete with the introduction of the F2 regulations in for the 1952 World Championship season which limited the engine capacity to 2 litres, and OSCA brought out the OSCA 20 for the new Formula. I showed photographs of that car on 22 October 2014 and you can see the family resemblance to the older car.