is there any resource which states what the recommended interior colors were for each (or the common) factory paint colors for 68-72 cars ?
That info can be found in many places. It's in the assembly manuals, it's on the factory paint chip + upholstery color brochures, and often in the factory sales brochures. Your best bet is to tell peeps here your exterior color and someone here can tell you the colors that were available. Bear in mind the colors back then were suggestions only, it WAS possible to get like...a green interior with a tan exterior by special order.
you can find 71-73 at www.boattail-riviera-by-buick.com its on the order forms in the library Dealership section - and under color and trim sections or each year.
