I have used, Traveler brand Universal Hyd oil from Tractor Supply. It specs out for Ford 134 oil also among many others for the last 15 years for my Ford 1700. I have not had any issues. It is basically used for transmission and 3 point lift and no loader.
For that tractor the power steering is it's own system with no wet brakes or clutches like the hydraulics/ trans. So really the fluid dosnt matter. How ever for any machine with wet clutches and brakes use the factory oil. It's not worth the $$ savings or lack there of in the long run.