I still have my factory manual for a 1975 xlc I once owned. It's pretty dog-eared. I also had the factory manual for a 1980 I once owned, but sold along with the vehicle. Now I have another 1980 and am using the 1975 manual to sort out wiring and other issues. Pretty much the same layout and so far it's given me the answers I need. Regarding emissions, if you get stuck, you can always ask someone to post whatever it is diagram you need. It's amazing how little changed over time.
I think it's funny (and typical) that in my '75 manual they have a section on the thermoquad carb (Scout didn't use it until '79 ('78 according to some)), the 1920, 1940, 2210, and the 2100/2300 variants. And tables and tables of distributor data, and truck/t'all emissions diagrams, and also the bw automatic used in the '70 or '71 scouts. Almost a hodge-podge.