Actually, we are just about at that point. We got everything mounted, bolted down and the loader on. Valve is bolted on and the cable/handle unit is now in place. Supply and return lines are hooked up and the loader is functioning. The 1/4" hose is still looking for a home. I see the plug mentioned on the rear housing(#2 on the diagram), but noticed an open port on the left side of the main case about where the PTO gears and shaft must be. It's also 1/2" pipe thread, and may also be an access point for something on the inside. A plug here would thread in from the left side, very near the rounded part of the case where the axle housing bolts on. It was getting late, light was fading, so didn't spend much time trying to figure out what exactly is in there, but I can see and feel something. I blew some air into port and it escaped through the dipstick hole, so I think it will work for our purposes. I could screw a 1/2 pipe fitting into it, but it's kind of in corner so only a straight fitting will work. The port is nice and clean like something was recently removed, but we have no idea by whom. The tractor and loader are both recent purchases, so history is limited. The hose is plenty long enough to reach back there, so I plan to go to town on Monday and get some fittings/adapters to connect it up. That and a bit of fabricating to mount a step plate to the loader frame and it should be good to go.
About the park brake adjustment? You say pull the handle back one click, then tighten the adjusting screw(under the #2 plug) until it's tight. Is that just until it contacts something below or until it's too tight to turn any more? What exactly does that do? Just take the slack out of the band? If the brake is properly adjusted, how far back should the handle travel before the brake is set? Right now it comes back quite a distance, maybe close to a foot measured at the top of the handle where the release button is.