Take them apart and lap the reeds mating surface first with 400 wet sandpaper on a flat surface then a final lapping with 600 wet paper using light oil or water with some dish soap added (I used a 1/4" thick glass plate). Then lap the reeds mating surface with 600 wet paper. This will provide very smooth mating surfaces to keep the reeds sealed when they are closed. I did this to my car back in 1994 and the AIV's are still so quiet you can't hear them.
