They sold quite a few back in the day--3/4 ton 4x4's that is--but they are mostly extinct now,and a '67 GMC 4x4 up here that isn't a rotbox ,and has the small back window are scarce and would be worth all of $2500 with no engine..at least!.
I wouldn't mind having one !..
Growing up I knew a guy who ran a small one man gas station,who had a red '67 GMC 3/4 ton 4x4 with a 283 V8 and a 4 speed--it was a factory Holmes tow truck conversion,bought it new from a local GMC dealer --he towed a lot of broken down cars and pickups in with that truck,he used to haul wrecks for the small town's police department also..that truck pulled some much larger and heavier vehicles out of ditches and snowbanks over the years..I remember it having factory 19" 8 lug rims & tires..
I think a 3/4 ton was the largest 4x4 you could get that year ?..