2504 (2509, 2044) 54/jun Maserati 250F GP Chassis #2504 Engine #2044 Color exterior - Color interior - Black   Date Result Event Driver # Reference 54/jun - Prince Birabongse Bhanutej Bhanubandh - "Bira", Siam (living in UK)   - this customer chassis was delivered to replace the converted A6GCM s/n 2044  - engine from 2044/'2504' taken out and dropped into the new chassis   54/jun/20 6th GP de Belgique, Spa B. Bira #20   54/jul/04 4th GP d'Automobile Club de France, Reims B. Bira #46   54/jul/11 2nd GP de Rouen-les-Essarts B. Bira #22   54/jul/17 19th R.A.C. British GP, Silverstone B. Bira #6   54 - chassis 2504 was damaged by Ron Flockhart while it was on loan to the Owen Organisation, the entrant for British Racing Motors, BRM. The Owen Organisation simply switched its chassis, 2509, for the damaged 2504. Therefore, the Bira 2504 was now actually the Owen Organisation chassis, 2509 (with all the modifications that the Owen Organisation had placed on 2509 removed), from the Caen race onward.   The record of 2504 as '2509':   54/aug/01 wdn GP von Deutschland, Nuerburgring Ken Wharton #17   54/aug/22 6th GP der Schweiz, Bremgarten Ken Wharton #18   54/oct/26 8th GP d'España, Pedralbes Ken Wharton #28   55/may/07 1st International Trophy, Silverstone Peter Collins #3   55/jul/16 dnf clutch R.A.C. British GP, Aintree Peter Collins #42   55/oct/01 dnf de Dion tube Avon Trophy, Castle Combe Peter Collins #14   56/jan/22 3rd GP de la Republica Argentina, Buenos Aires Mike Hawthorn #14   56/feb/05 9th GP Ciudad de Buenos Aires,  Mendoza Mike Hawthorn #14   56 - Jack A. Brabham, NZ 56/apr/21 3rd B.A.R.C. "200", Aintree Jack Brabham #9   56/may/05 disq oil leak International Trophy, Silverstone Jack Brabham #16   56/jul/14 dnf mechanical R.A.C. British GP, Silverstone Jack Brabham #30   56/jul/22 3rd Vanwall Trophy, Snetterton Jack Brabham #37   .. - Quirk, NZ .. - Gilbert, NZ 63 - Len Southward, NZ