That shifter doesn't look that bad, as long as there is not water sitting in the bottom of the sump.
I think, if there is another nub on the other side of the tower, you turn the top "disc" that the lever comes through counter clockwise looking from the top. It should turn about 45 degrees and come off with a spring pushing from below. It should turn with not a lot of force, you might have to push down on it a bit while turning.
yeah..we saw when we grinded down the nubs and drilled them out

oh well, we'll fix it later.
The gearbox from the top doesn't look to bad..nothing that a steel brush and some elbow grease can't fix.
to be honest, we just need 1 gear to work, because its only job is to roll independently onto the DMV inspection platform for the shortened frame inspection.
as soon as they certify that, we putting in the 6.2 Diesel with the TH400 (curious how that'll hold up against the 6.17 to 1 rear end..)
When we took the cab of I could take a good picture of the brake booster which says: Bendix Aviation Corp.

I guess it works the same as the modern brake boosters, only it's not integrated with the master brake cylinder.
Also took a picture of the PTO which drove the hydrolic lift in the back.
we found out that the picture called PTO brake, is actually the parking brake. never seen a system like that and wondering whether it is linked to the PTO? so when you engage the parking brake, the PTO starts building pressure?.