Dear Sir, We bought a house that has old plaster walls. Most are in desecent shape. BUT the dining room has that ugly wall paper board over it, the board didn't reach to the top so they placed trim ( glued it on ) on the top close to the ceiling. We are trying to fix it but can't so we are painting over it. The only thing is around the doors and close to the trim are about 1/2 inch gapping how do we fix this so it looks good?