While sorting through a new box of vintage (1952-1965) that just came in the mail, I came across a 1961 Topps #325 Wally Moon card that had glue spots on the back. It was probably put into a scrapbook for someone's collection a long time ago. There were 4 half-inch glue spots on the corners, and another in the center. Whatever paper the card had been stuck to was still on the back of this vintage card, obscuring the writing behind it. It looked like someone had already tried to pull the glue spot off of one of the corners, ripping a portion of the card back with it.
Stop. Please don't ever do that. If the obscuring glue spots bother you as much as they bother me, try this. Remember, Elmer's-type glue is water-soluble. If you put dabs of water on your finger and rub lightly on the spot, it will eventually dissolve and come off. Adding too much water or rubbing too hard will begin to have a negative effect though, so use patience. This method often removes 75% or more of the glue stains, and at least allows me to read the card again