I recently bought a Darne 20ga R-15 as imported by Stoger. The receiver area seems to have a yellowing coating of Lacquer or something on it. Can this be removed with something without affecting the engraving? Also, the butt plate appears to be original to the gun, but undersized. Could this have shrunk? Lastly, the forend tip is loose in the recess, not in danger of falling out though. Glue or leave as is? Sorry no pics beyond my skill set Thanks Tom