What's the problem ? I've used these tractors for many years and still do. Finding and filling all of the oil reservoirs is easily the worst part of owning them.
The thing to keep in mind is that there are two reservoirs as the tractor has a front half and a back half.
I once had a problem with the front oil tank losing oil somewhere. As it turned out, the crankcase oil was increasing as the hydraulic oil was decreasing. As I recall, there was a seal or a pump between the two that had failed. That's why the front hydraulic oil is 15W40, because it sometimes ends up in the engine crankcase.
Anyway, just to summarize, the first step is to locate the fillers for both reservoirs, and that isn't easy. Next, you need to find a way to allow air in the reservoir to escape while you are filling, or use a filler pump. (A funnel set-up will take you an hour to add a quart of oil.)
It might be worth checking to see if your crankcase is over-full. Maybe you have the same problem I had.