The '59 supplement only covers the few changes from the '58 models. Everything else is in the '58 book.
I don't know about the '65 but if it is labeled supplement I suspect it is the same way.
I like comparing the shop manual to a Motors Truck Manual. Having both references gives me a better idea of what I'm doing. The factory manuals were written by tech writers while the Motors Manuals were written by mechanics. Often the latter will have tips you won't find in the shop manual.
