We inherited a room with an old tin ceiling that was painted white. We are going to paint again, but the edge of the cornice that meets the wall is very damaged from rust around most of the room, and there is a gap between the cornice and the top of the drywall edge when new drywall was installed in the room. My thought is to buy some new narrow cornices that we would install around the room over the bottom of the old cornice and spanning the small gap onto the new drywall. Does this make sense to do? Alternatively, we thought about using drywall tape and mud to cover the gap and the bottom of the cornice. Picture links below.