Isx cm871 rear structure and front oil leaks

[jesse24spd]

Truck is an auction purchase with a 132” sleeper.

2008 kw t600 with 18 speed. Recently purchased this truck and have some insight in to its history.

Preparing to put it in service and need to take care of a couple of oil leaks first. What needs to be replaced when doing these repairs? Rear structure is leaking at gasket. Planning to do clutch while transmission is out to do the gasket and rear main.

Front gear structure appears to be leaking at gasket as well. Are there any hard parts that have to be changed with the gaskets?

The history on the engine/truck I’ve been able to piece together is as follows
1,533,000 miles
Rebuilt at 800,000 at {garbage-can shop in PA} (demandated at or around this time) oil bypass filter added as well as fass lift pump installed.