Hey Brian,
Doug is correct on the weight of oils. One thing to note is you must use a GL-1 classification at least in the transmission. GL-1 was the standard classification when your tractor was made, so, there is not any mention made of this in the manuals. The reason for this is to do with the design of the steering system. Later classifications such as GL-3 or GL-5 which are more common are too slick, thus they will not allow sufficient friction between the steering band linings and the drum, making the tractor difficult if not impossible to steer. You should be able to get GL-1 from your local oil distributor, I get mine from an oil warehouse. They should know what you are talking about when you tell them GL-1, I use a multi weight. Remember, you must use oil in all your rollers, this same oil will work, but it must be oil, NOT grease, and it must be pourable. Otherwise you will risk burning up the bushings and shaft in your rollers, and idlers.
Take care!!!
Andy