Help with leveling 1984 Ford Corsair

RV owner's manuals are usually not all that helpful, sad to say. Mostly they tend to be rather thin and generic (covering all the company's models, or at least a rather large range of models) and then they throw in the manuals and other information for all the appliances and accessories that were built into the motorhome. Those appliance manuals can usually be found online without too much difficulty if the need comes up.

There are a few exceptions, but that's the usual way things are. A few companies (Winnebago and Airstream being examples) have available good service information like wiring and plumbing diagrams for the asking, but that's the exception rather than the rule.

There are some decent books along the lines of "RVing for dummies" that cover most of what the owner's manual would, and probably more: things like winterizing and dewinterizing and sanitizing the plumbing, etc.