I'd say you chose wisely.
Even on that size of tractor there are a couple parts that are akward to handle, but really they are the essence of simplicity.
Even at that, I'd say buy a manual [I have mixed opinions of them, but this being your first one, seeing some things apart before you do it could help] and/or make generous use of a video camera or I like a digital still camera [don't have a digital video, but that would really be a good answer too]. These were farm machines, so you'll likely run into fixes or mods that you're not sure whether factory or farmer. Might take some research there.
Also, may want to read a restoration book or two, or browse some old iron magazines or web-sites. I always thought that was the "pansy" way to do things, but I can see lack of thought in so many places on a couple of the first ones I did.
You ask about costs.....well depends whether you just want a "20 foot job" [looks great from 20 feet], show-room, or [most likely] something in-between. The former might cost nothing more than a couple gallons of fresh gas, a $20 gallon of tractor enamal and maybe a set of stencils. The latter can get excrutiating both in time and money.
I'd say you don't have to tear out every gear in the tranny etc., but I would rebuild [new/or oversize rings may be good enough depending on the condition of the pistons and walls] the engine and any other parts that seem worn or too loose. Not always cheap, but you should be able to find a good mix of original and aftermarket parts for that.
I've seen good results using just a pressure washer and wire brush then a coat of enamal [I've been burned by cheap tractor enamle, but actually was satisified once with Rust-Oleum and it's "rust adhering" primer]. On the other end you can bring everything to bare steel [if you have humidity, there's a real narrow window before you need to prime] and go with something recommended for construction equipment [like a tough 2 or 3 part urethane or add hardner to a good quality enamal].
Anyway, it's impossible to give you a dollar figure, but even if you spend more than you intended....standing back while it's idling like music as the sun glistens off your shiney paint job....the $$$ are forgotten fast! /forums/images/graemlins/cool.gif
