I've a steel bike that's about 50 years old and another that's about 30 years old. Neither one of them spend more than a couple hours at a time in a non-climate-controlled environment. I fully expect both of them to go to the grave with me. And I'm 44.

As for original saddles I almost never ride a bike with the original saddle but when I sell bikes I either sell with original saddle or offer the original saddle up if they want it. Same with other stuff, even tires. Nobody's taken the goods though. People buying 20 year old MTBs just don't seem to care that much.