Praire BobCat Jumbo 2000 3 speed Transmission ID

[alberta6+6]

Hey I have two Jumbo 2000 6x6, these units were for pipeline work in muskeg i guess... can anyone identify these transmissions? or better yet do you have one or parts for them?
update - found a pic of the nearly the same trans in a 1954 economy tractor.
My two 6x6 are apperently from 1984