Fleer 1970 World Series set

[Mesquite]

I collected these world series cards as a kid, and have most of the 66 card set except for 5 of them. At the time, there weren't many ways for a kid around 10 years old to learn about the past world series' so the paragraphs on the back of each one were educational.

Some photos below. They are in mediocre condition since they were frequently handled, so they aren't worth much. The misalignment on some of them is pretty bad too (not just left to right, top to bottom, but even tilted in some cases).

Anyway, I just thought I'd share them in case you've not seen them before. I don't suppose it's something serious collectors collect, since they are more of a light-hearted "schoolhouse rock" type of theme.

But I also wanted to ask about these clear sheets they are stored in. They're beginning to yellow (I put them in these clear sheets in 1991), but it doesn't seem to be affecting the cards. Is it a bad idea to use these clear sheets for long term storage?

Thanks for looking.