OK, my 3165 was a 1973 New York State Thruway mower. They never used the independent PTO or the 3 point, so they are all gummed up. I 'think' the engines, either gas or diesel, are all Perkins, and I believe so was the rest of the tractor. I have Conventry spires on my castings, and others I have seen. It is just an industrial version of MF165, and any manual with that model in it, will cover yours.