I really do not see the market for them. I have seen Broncos go for less because the buyer has to remove the camper. That being said for those interested there seems to be plenty out there you could grab and "restore/modernize" We ran into a guy here in Denver who sent his back to the factory and had it fully restored, siding, top etc. He claimed to have over $10k in that alone.
I have said this before, my dad had a 77 and we camped all over Colorado in it, 2 adults, 2 kids, and 2 golden retrievers. We camped well above treeline many times and it was awesome!!. Mind you back then they did not have the offroad popup selection that is available now but it was still cool.
My dad has one but I just can't get the wife to allow the kids to sit sideways with little or no protection like we did back in the 80s. There is a totally different standard of safety I guess. (my parents also bought a conversion van minus the seats on the inside and thought it was safe for my sister and I to sit on beanbags in the back for many years)
If it was me I would buy a Jayco or Fleetwood offroad camper or rooftop tent. Much cheaper and more modern amenities, plus you could go much deeper into the rough stuff.
Dennis