You never considered driving this home, correct? All the fuel stuff is just for a test drive?
-I think its a great start as long as there's no surprises. Definitely looks like a vehicle that saw a Michigan winter or two, but it's certainly far from gone.
-Get a non-return fuel filter to swap in and some new fuel line and clamps to run into a bottle for testing.
-If this hasn't moved since 85, do you know that the brakes aren't frozen? He's run it, has he at least rolled it around?
-Similar to the brakes, if it's not moved in years you're guaranteed that every seal in this thing is dried out, cracked and/or powdered. Wheel bearings could be in very rough shape as well. I personally wouldn't think about flat towing or even using a tow dolly, I'd have it on a flatbed of some flavor. It would be different if you knew it had been on the road within the last year or so, but if it's truly original, there's a ton of things I wouldn't trust to run at highway speed. At a bare minimum, if I had to do it, I'd pull the driveshafts, drain the diffs/check the gears/refill the diffs and I'd probably pull all the brake parts in the rear just to be safe.
My thoughts anyway.