Get or make two 3 foot by 2 foot by 2 foot boxes with lids and dedicate one for parts/filters and one for fluids. Get a decent waterproof tool backpack and hang it off the back of the seat. Get some 1/2 inch drive tools from harbor freight (metric) and start making up a kit for the stuff you use all the time.
Start making inquiries as to where you can get hydraulic hoses made up locally. Usually a NAPA has the capability, but often are a bit lax in their inventory of fittings. You will seldom need them, but you don't want to be looking for one if you need one fast.
I 've been told there's a code or standard that the oil must meet or exceed in the manual. I grab the oil from my parts supplier, as well as the hydraulic fluid. It's never the same twice. In that, I do change the oil frequently.
As for additives for the fuel. I put that treatment in for low temperature use as a matter of course. I keep 15-20 gallons on-hand and treat it as I buy it. It's not all that expensive and the thought of having gelled fuel doesn't appeal to me in the cold months. It's one less thing to keep track of.
Get a grease gun just for the tractor and the best grease you can get. An old medicine bottle with a couple replacement zerks is a good thing for your parts box.
If you have a harbor freight/tractor supply, get an inventory of those snap ring pins that hold the pins in place.
