That's the one, I knew that I had seen another one that did that, couldn't remember the model. 
On the Lionel postwar transformers, generaly if the transformer has controls for one train the U post goes to the center rail. If the transformer controls two or more trains the U post goes to the outside common rail.
Al
Interesting Al, I never made that connection. Perhaps the connection scheme did have some reasoning behind it. OTOH, why in the world didn't they make it consistent? 
Based on my experience...put a piece of tape over the speaker opening. Cover as much as you want to reduce volume. That is how the old Victrolas did it. Open the door to increase sound, close as much as you want to make quieter. If the other guys hate it just cut the wire. Keep it simple. Chances are no trips for parts, you most likely have a piece of tape.
