
As I work on the Riviera Project, some of my more important primary sources are the brochures Buick published between 1963 and 1999. These brochures give me many things including specifications (though sometimes these are inaccurate or imprecise) and equipment (though sometimes this is inconsistent or misleading).
I think the most valuable feature these brochures offer is context. You get to see what features Buick was emphasizing for each model year and what they thought was important to their potential buyers. In the brochures that cover the entire Buick line, you can sense the Riviera’s place within the range. Some very draft text from the Riviera Project about the 1967 model year is instructive:

Hans Tore Tangerud’s wonderful
lov2xlr8 website.
Buick brochures made significant mention of safety for the first time since the Riviera had been released. Four-way hazard warning flashers were now standard—a year in advance of the federal deadline. Brakes got a lot of attention; the Riviera now had a dual master cylinder system, the number of fins on the aluminum front brake drums were doubled, and the power brake vacuum booster was larger. Finally, front and rear seat belts were now standard equipment, with shoulder belts optional for the driver and one front passenger.
Rivera Project, late April
Aside from being valuable as source material, these brochures are also a lot of fun. I must confess that I especially enjoy the ones I’ve purchased in physical form—there’s something about opening a 68-page full line brochure from 1975 that someone has lovingly preserved for over 40 years.