Hello Timkim,
I'm sending this response from maccamper who's out working on our awning hardware right now.
We have a 1974 Ambassador with the same woodlike finish. It's a good probability that it is a plastic laminate made to look like walnut -- very popular in the 70's. A couple of sources of information on the laminate would be
Wilsonart.com: Welcome! and/or
Formica Corporation - North America Naturally, the new laminate would not have the "patina" of the 1972 finish.
Good luck with your search ...
Nancy Mac (mrs. maccamper)