I was going through a file cabinet in my house and found a dealer brochure for '68 Chevy II Nova in mint condition. No discoloration or brittle pages. Aside from me, I would swear no one has ever opened the pages. It's kind of neat.
That sounds rare indeed. Welcome to the site! If it's something that you were wanting to sell, since you are new, this site has a great classified section that you may want to post in. Again, welcome to the site.
Handle with care. Any accumulated damage does not repair itself. You might consider individually bagging it, then placing it in a larger bag with cardboard backing to prevent knocks, scuffs and creases. The rest is up to you with clean fingers and ginger handling. I have been collecting that sort of stuff for 37 years.