Are the aux trans specific to 9N, 2N, or 8N, or are they interchangeable? There is a 9N or 2N in a salvage yard with a high-Low aux that I would like for my 8N, if it is compatible. My brother is there and texted a pic of the tractor, or what is left of it. I an not sure if it is a 9N or 2N, but it is clearly not a 8N. He said the aux shifter popped into 3 distinct positions when he moved the lever. Any advise is greatly appreciated.