Not sure if you got what I meant. You could still use your old wagons on the O gauge just by swapping wheels/wheelsets, so you could still use 1960's products on the new system. Similarly the O gauge motors could still have the same 4 stud wide form factor, but with the wheels inset slightly, so again the O gauge motor could be a direct swap for the 1960's stuff. Not only that, but you would gain more space for motion, something sadly lacking on the 9V sets.