Your serial number does indeed come back to a 1946 2N. SNs never did have a 2N prefix; I was told that this was because Ford intended the 2N to be a wartime temporary model only, but for whatever reason they just continued stamping them with 9N and whatever number was next. The 8Ns however did start over with 8N1 in 1948.
Sounds like you have a lot of little fixing to do. Those lug nuts scare me, they most certainly should not snap off and I wouldn't want to operate a brush hog if my front wheels were questionable.
Fenders are easy, replacement originals are available from multiple vendors. Tool boxes are not as easy (battery acid leaks onto them and they rot out) but not as crucial if you 're just working her. The oil leak is not good but so long as it's not severe and your clutch doesn't get inappropriately lubricated it's not terrible either. Some folks say overrunning couplers are a must, others scoff at them -- I'll stay out of that arguement but theyr'e easily replaceable. The ORC is NOT an original equipment item, just unpin it and it will come right off your PTO shaft, but be very very careful if you run a brush hog without one until you're used to it. With no ORC, when you put in the clutch you WILL NOT STOP -- instead the flywheel momentum of the brush hog will push you forward several yards until either it stops moving or you take it out of gear. Many people have gotten hurt because they were'nt prepared for this little old tractor quirk. Also, the original PTO shaft is 1 1/8" as opposed to the new 1 3/8" but there are adaptors.
Good luck,
Pete P.
Harborcreek, Penna.