Ford R1-424 is now
ONR. However it was repackaged by Exxon-Mobile for Ford.
It is still available from Mobile suppliers but it is now renamed as Mobilefluid 428.
This fluid is used as the hydraulic fluid by several tractor and dozer manufacturers.
Beware that using tranny fluid can have adverse effects on the seals used in the steering rack, power steering pump and various "O" rings.
The parts guy I deal with at my local Ford dealer advised me that the only dealer still showing any stock of R1-424 is Hidden Valley Ford in Darwin.
They now have only 4 X 1 Ltr containers left.