I found this grainy, faded image of the original Commons in a scrapbook I hadn’t opened in several years. Somehow I had overlooked this rare image–note that the wooden paneling hadn’t yet been installed:
The original surface seems to have been plaster. You can see it here in this picture from a post I wrote when they were renovating a few years ago:
Bonus: Better be good! Willy and Santa both keep lists.