wow, bubba really been there

what does
this linkage do? what does it connect to on the PTO block off plate? what moves it? meaning, which end is driver and which end driven? if an overdrive how is it shifted? really don't see how an overdrive could function
before the transmission
is the other end of that hose hooked to the brass plumbing fitting under the back of the trans? how can a single hose provide "circulation"? in fact I can't imagine 90/100 weight gear oil moving thru that small a hose, even warmed up
kinda looks like a hydraulic pump to me, what profession was the service body on the truck for?
Bill