The most cost effective method is to glue the key back togather. Remove the key on either side of the broken one. Place the keys on a flat work serface and work Titebond or PVC-E glue into the broken ends andforce the parts togather, wipe any access glue. Place the two side ekys against to the repair to make certain they key is straight the of the proper length. Allow to dry. Remove any excess glue, in the balance hole or the sides. This is not a real strong joint because of endgrain so it needs reinforcement. I like to use 1 1/2" banding veneer with hot melt glue. This veneer is thinner than regular veneer so it works best, taking up less room between keys. Iron this veneer onto the sides of the repaired key, making sure there is clearance with its neighbors. If needful you can sand some of the wood off the repaired key and the adjacent keys. When you are finished the repair is complete and the key can be played immediately. If you have any questions please contact me. Newton nhunt@jagat.com
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