Joe,
I've replaced wood in some Model As and one '30 Chevy. There are suppliers for them. However, I know of no one cutting out wood for your poncho.
I was wondering how close to a Chevrolet your car is?
Years ago, a friend rebuilt an old Franklin and had to use his old, rotten wood parts to make new wood for his car. Takes all kinds of wood-working tools and patience....and lots of time.
I know this isn't much help, but good luck on your endeavors.
