My thoughts on pre production cars are that almost anything goes. I have seen some very odd stuff on "pilot" cars. IMO they should be restored to retain as many of original details as can be found and enjoyed by all as an example of what was done when a new car was brought into the fray before regular production began. Duplicating or referencing these oddball details when restoring a regular production car would be a mistake.

*Restoring a rough pilot car can be a daunting task since there is nothing to reference in terms of their actual original details, each is truly a one of a kind.