When you remove the rest, you will very likely find that the riser has darkened with age, and the area where the rest was will show up as a light spot. Usually the adhesive comes off ok with some solvent, but the only way to fix the "ghost" is to strip, sand , and refinish as the darkening is oxidation in the riser wood itself. My solution,if the finish is in good shape otherwise is to install a new strikeplate/rest that covers the area and live with it. Just my experience.