hi bob
my understanding of the materials used in the prototypes is that current production commercial components were utilized as much as possible. i googled a pic of a civi 1938 chevrolet truck and the tail lights were of the same shape and size as best i can tell. one thing that may have been different is the composite lens for military use and black out service, but i'm not sure if at this early stage, blackout would have been considered. as for the other car...i have no idea.
mike