Definitely hang onto some of that literature. You want to be able to show people what they used to teach. It's one of the best ways to prove how misguided they are.
My mom had English bound volumes from way back to the 50's and she wanted me to take them, but I had no place to put them at the time, so she ended up throwing them all away. I regret not taking them and putting them somewhere.
If you decide to get rid of some of it, or you have extra's, let me know.