Quote Originally Posted by davep View Post
002 0005 & 006 0015 are body production numbers, also known as production order numbers. These numbers were stamped on the body below the radio opening on the lower part of the dash usually hidden by the knee pad; and also handwritten in lumber crayon on the cowl. Normal production bodies and production order numbers for standard cars have a leading 1. A leading 0 indicates a replacement body shell. The next digit, 0, indicates a coupe body type. The third digit is the model year of production. So, yes, a lot of race cars were built on replacement bodies to save time and cost. Replacement bodies were available from the early days when Porsche supplied Beutler with basic chassis on which cabriolets were built.

It makes sense now, thanks !