It’s just a basic gear pump and simple motor drives
Any engine oil will do or just use what ever hyd oil you run on the farm.
The colour of it will determine if it’s got engine oil or hyd fluid in its tank
I used to use
Fuchs Utto
Hytrans CNH
Hygard JD
Or what ever else was around at the time
I did change from engine oil to hyd oil for the simple reason during harvest there was always a lot more Hyd fluid consumed in the paddock more so than engine oil. Blown hoses, leaky draper motors, o-rings, leaky multi couplers etc etc
You know the drill.............