Ehhhhh tough call. Some meat left on it, but its definitely a project.
Hope you can weld, turn a wrench, and be a sheet metal god.
My only thought would be trying to find an old C500 with a butterfly hood as a donor truck and if you're lucky the the engine / trans goes in easy, butterfly hood gets widened (forget the covers) / blended into the new truck. Recycle the radiator, etc. Torch the headlights off the 5 and weld em in or whatever is easiest.
Might find a decent deal on a vintage bed / winch / rig truck closer than BC
Old truck, lots of steel to weld and modify - just like the Hayes, Pacifics, Macks, etc. Just depends what you're after in terms of authenticity or aesthetics.
As far as finding genuine 848/49/50 replacements, I would say rare unless you head to the Coast and hunt around with a pocket full of cash, even then....