That last picture probably shows off why you need 10 gallons of gear oil!
In Europe at least that rear axle arrangement is know as a Portal Axle, and certain 4x4s used in rocky and mountainous country have them for huge ground clearance, but it gives you a gear box, differential and two wheel gearboxes to lubricate!
I think the belt drive was fairly common on tractors of this age and through the '50s. certainly when I was a boy on the farm in England most of the older tractors had it as well as the rear PTO.
The Kerosene was known in England as TVO, Tractor Vapour Oil.
Back in the military in the '70s I knew a guy who grew up in rural Northern Ireland. In his teenage years he came by a Jaguar SS100 that had twin fuel tanks, to run it he bought a small can of petrol (gas) and put it in one tank and 'liberated' low taxed TVO from the farm to put into the other tank!
(surely this is much more interesting than another oil thread?)