As new, it was near holy grail optioned, is a short bed (more valuable), fleet (more valuable), big window (attractive plus), 6 cyl (less valuable but original)........not looking too good in the rust category.
From 2000 miles away, knowing that pictures always look better than the actual, which means the rust is worse than it looks, which means bad rust...........using my eyes, my gut, my experience and crude honesty..........
This opinion is an arm chair valuation (actually from my La-Z-Boy command center)
It is very high on the too rusty to buy "scale". Many many hours of work. The final product will be upside down. Value now: $4000-$7000. As always, the Haggerty/KBB/NADA/Hemmings have no meaningful data on a truck in this condition. Folks like those here who have bought, refurbished and sold old trucks and know the year to year market changes, can be more qualified. See what others say. Sales are regional. Canada to USA shipping is large. I don't know the buyer base in Canada. Barrett Jackson, et al, auctions are no indication.
The rule for what it's worth is what a willing buyer will pay a willing seller on a given day. Actual documented past sales are proof of one given set of folks regarding one certain truck. Everything else is a guess. That's mine.
There are restored examples being offered at $79K.