It was "STICK-UM" wall paper. Another peculiar idea from the 60s was wallpaper that had the adhesive already on there, like a paper bumper sticker. Which is why all the real old Fenders have big cracks and sometimes half or more of the face popping off. The glue didn't survive too well, and would let go. Painting is a much better idea!
You could find the original Fender flower and paisley in wallpaper shops and warehouses in the early 80s. Most of it got thrown out.