Other than that pricing sticker, which came to be around 1975 when pricing was being changed from 2 games for a quarter to a quarter a game/3 games for 50 cents, your instruction card holder doesn’t look like it needs restoration(at least from what you have shown us). Take some lighter fluid and remove that sticker.

Don’t use waterbased cleaners on your inst card holder as they will remove the art. Alcohol and lighter fluid should be OK.

BTW, that sticker is an add on and you won’t be missing much without it.

I use plastic razor blades to get the edge up and then lighter fluid/naptha to continue pulling it and to cut any remaining adhesive.

You can find the plastic razor blades at Lowes or Home Depot.

That has been my experience. Nor alcohol or WD-40. You have to be careful with water and Novus on the other hand. With the alcohol or WD-40 try an area and see how it reacts. I only use lighter fluid or alcohol for adhesive residue. I've used WD-40 along with a dental pick to get hardened glue off based on a recommendation I got here.

Personally, Novus is my preferred cleaner to clean Gottlieb instruction card holders, although very sparingly. If you need to really work something Novus is fine on the white areas. If I need to work a white area near the color I use a q-tip.