Eric.......you ask......."the tractor is also equipped with an auxiliary transmission. how many different types of auxiliary trans were available and were they the same as auxiliary trans that fit the later serial numbers?".......AFAIK, Sherman's were the "ONLY" aux tranny available until after WW2.
AFAIK, Sherman's had an "HELIX" output gear and early 3-speed trannys were "straight-cut" input gear. There was a "kit" available to convert early straight-cut trannys to the "better and quieter" helix input gears. That is the ONLY way Shermans would fit early 3-speed trannys.
You ask......"does any one know how much this tractor may be worth?".......while an aluminium hooded 9N is a great find, it is still a 3-speed 9N. Since I am NOT a sphincterly challenged tractor collector, its worth about $2000 to me iff'n the $500 rear ag-bar tires are good and the engine runs. ........respectfully, Dell, the non-authority