These M72 have what is referred to as a "crash gearbox", no doubt named for the smoothness of the gear-changes. They don't have reverse like later models, but they do have a neutral finder hand lever that can also be used to shift manually.
Footshifter is a heel toe deal.
The clutch actuation rod passes through the mainshaft. The bell housing was full of sand and muck.
On the other end is the clutch rod actuating lever, the kickstarter shaft, and the splined output shaft.
This round doohickey here fits over the splined output shaft, then a hard rubber donut fits over the big pins there, then the drive shaft inserts into two more holes in the donut, which acts like a cush drive.
There's the clutch rod and bearing, too.