You should use GL-1, AKA "straight mineral oil" in your 35.
Once ubiquitous, this is becoming a bit more difficult to find.
Look for the GL-1 rating or oil marked "yellow metal safe" (SOME more modern GL-4 and GL-5 oils are marked such and are better alternatives) or Ford Transdraulic.
Such oils are available at your MF dealer, NAPA and SOME farm stores.
If you want to do it right, remove the inspection covers and the PTO shaft and spend a couple of hours with a solvent filled garden sprayer, paper towels, etc., cleaning the sumps. You will likely find about 1/2" of sediment in the bottom.