Granpa- thanks for the response.
The car is pretty badly battered so I've got a new chassis, 2x C parts and 2x b screw bag on order. I also noticed one diff bevel gear is slightly damaged on a few teeth and the gear shafts are worn. So factory fresh to me is replace damaged / worn parts, which will pretty much leave me with a new rollling chassis. I'll keep the old parts as spares. The shocks are being replaced with mini cva's and the drive shafts swapped for UJs.
Can I ask what is recommended for lubing the diff and gears/bearings/axles?