Yes, it's a very tough truck (IH engines, although gas not diesel, are known for going more than 200,000 miles before rebuild). Yes, it's small and has a neat built-in camper. Yes, Scouts are pretty neat machines.
However, when was the last time you saw an IH car dealer (not farm equipment)? Where will you get parts for it if something breaks? This thing is a toy; something to keep under a tarp in the garage and pull out on nice weekends to see if you can make it up the Rubicon or something. This is not a machine you should rely on when civilization is collapsing around you. FFS, that's a 40-YEAR-OLD truck! It's also a magnet for anyone else who sees it, since they'll think the same thing you will: "hey, that would be a really neat getaway vehicle, if I can only get it away from the current owner".
I'll say it again: IT'S 40 YEARS OLD!
Buy something newer, or, at least get something that you can find parts for more easily. The older K5 Blazers have a much larger parts supply out there. You can get a mid-80s ex-military pickup truck for cheap and stick a Lancer camper in the bed. Heck, you can get a newer 4x4 1-ton pickup from the local utility yard and stick a Lancer in it.