A friend of mine in FL used to build and sell wooden armrests and recently found a batch of 6 he had made a few years back. He doesn’t remember what material they are but they look like mahogany to me.
They fit right on a dreadnought guitar and possibly other guitars as well. They stick on with self stick 3m tape and are supposed to make the guitar sound better as it gets your arm off the top of the guitar and only a small section of the armrests touches the guitar.
$25 each plus $5 for shipping.