Actually after I had contacted everybody I could think of -- a local construction worker friend, the sheriff's office, the fire and rescue people, the actual fire department, the animal shelter, the newspaper, a factory that actually makes cherry-pickers (but it turns out, not at this location) and the utility companies in search of somebody who would have the equipment to get up there (nobody except the electric company did, and they wouldn't do it), I started calling tree services. Nobody answered until I called a place in the next town. Contacting them was iffy as my cell phone kept going down at the same time.
Finally they came up late in the day with their bucket truck and parked next to the tree. The guys got out and immediately started taking pictures -- I guess never having seen a cat that high before. They started to get their truck's pod-legs in place to get ready. All of this makes a lot of noise from the big diesel engine, which spooked Hobbes, who jumped nervously, lost his balance in his six-day fatigue, and started to fall.
In mid-fall he caught his balance as cats do and actually started running -- straight down the fifty feet that had terrified him. When he got to the bottom he just did a right-angle turn from vertical to horizontal and kept running up the hill. He didn't even hit the ground.
He continued running up into the woods and I was afraid in his freakout he would scamper up another tree, but he didn't -- he stopped in a clearing and just sat there, exhausted I have no doubt. From there I picked him up and brought him in, and that was Wednesday so he's been mostly eating and resting ever since.
Thanks everybody for your concern. In the end I didn't need a cherry-picker; all I needed was sound effects.