#31 is a monolith.  22″ tall, 12″ wide, and 10.5″ deep.  The sound hole is on the structural side, so you could play 2 oak faces or 1 birch face.  It is finished with a medium walnut oil.  In this video, you can see Paul playing the birch face with a fist on the bass.  It plays phenomenally in this style, and the bass sounds just like it does in the video.