I have two candidates for the base of the 1953 Pontiac ornament. One is an oak block with slight spalting; the other is a pecan block with extensive spalting. "Spalting is any form of wood coloration caused by fungi. Although primarily found in dead trees, spalting can also occur in living trees under stress or even in thriving trees." (Wikipedia)
I have roughed out the pecan block to fit the ornament. The pecan is still moist (which is what allows the spalting to occur) and slightly soft (which will require stabilization after it dries). The oak block is dry and firm. I will also cut the oak block to fit the ornament and then decide which to proceed with.
I am still trying new show venues to find those that provide the most effective exposure for my works.