Here we refer frequently to chassis numbers. Having a major tidy up here at home over the past 11 days - with many more stretching ahead - I just came across these two 1964 shots of - I believe - the prototype (or maybe the 2nd-off?) McLaren-Oldsmobile M1A built by Bruce McLaren Motor Racing.
The first shot shows the cockpit with the chassis plate attached to the dash panel top left.
The second shot is an enlargement of the plate itself.
Just for interest.
(Photos via The GP Library)
DCN