Just picked first brand one 303 tractor fluid search ,
Super S SuperTrac 303 Tractor Hydraulic Fluid has been field-tested and is suitable as a replacement fluid for the following manufacturers where a tractor hydraulic fluid is recommended: Allis Chalmers, JI Case/David Brown, Allison, John Deere 303, Caterpillar, Kubota, Deutz, Massey Furgeson, Ford Tractor, Oliver, International Harvester White.
Super S SuperTrac 303 Tractor Hydraulic Fluid will provide excellent results in the areas of: anti-wear properties, rust protection, brake chatter, water sensitivity, extreme pressure properties, foam suppression, PTO clutch performance
It appears to cover most brands of tractors including the green one....