Main gearbox: Either ATF Dexron III or MTF94 or equivalent - I'm assuming you have the Rover R380 gearbox on your truck, please check the box before adding oil. If it's not either a LT77 or R380 then get back to me
Transfer box: EP90 or EPx80/90 GL4 - do NOT use GL5
Axles: EP90 or EPx80/90 GL4 or GL5
Steering swivels: EP90 or EPx80/90 GL4 or GL5 is the OM standard, however most find a one shot grease is a better bet. You can buy your one shot or make it my mixing equal volumes of a good quality LM or MS grease with the above oil - warming them up helps to mix them evenly and makes them easier to put in the swivel housing.
Can't help with the service manual, I'm in the UK