What do you need and what oils meet those requirements?
As best I can tell, Hy-Tran emulsifies water and keeps it in suspension, others such as Hy-Gard will demulsify water and force it to separate out to be drained.
Which is better?
Is Hy-Tran the only emulsifying hydraulic oil on the market?
I doubt that Hy-Tran is the only emulsifying oil on the market and I have no idea which is a better solution, emulsify vs demulsify. I also would be suprprised if JD, Kubota, Cat, etc.. are using Hy-Tran in their equipment but they still seem to have a good reputation with whatever "lessor quality" oil they recommend.
It is not my money so folks should do what they feel is best but at $20 a gallon for Hy-Tran, I would have to see some data that shows a clear advantage over the generic oil. For a 60 year old fairly simple tractor I expect the Hy-Tran offers no advantage.
If someone has some real data and an explaination as to why Hy-Tran is better for a cub, I would be interested but I could not find any at Google University.