kgdjpubs, you just discovered something that I never really noticed, but it is correct.
Here is the original, hand-drawn diagram from the Lima Locomotive Works that I used to make the diagram in the computer. That same offset is there.
I think the offset is there because there are a couple of appliances on the Fireman's side, such as the cold water pump and the feedwater hot water pump that demand slightly more clearance on the left side.
