You bump your instrument against an object and a corner-piece breaks off, one of the most vulnerable spots of Violins, Violas and Cellos. It looks bad and it weakens your instrument. The longer it stays like that the bigger the damage. The best time to fix your instrument is at the beginning when the naked wood is still clean and broken surfaces are not degraded. You also want to prevent losing the original corner-piece that broke off in the first place. The best thing you can do is to seal the broken off pieces in a airtight bag where no dust can get in and bring it to my workshop. What if you have a corner-piece that was broken off years ago that is dirty, dusty, and greasy? Not to worry as I also have experience with these so called "worst-case scenarios". These situations do take considerable amount of time in order to clean the wood, flatten the surface, and find the perfect matching piece of wood so that the retouching work covers the damage. In any case, irrespective of the state of your instrument, you will receive it back with a fixed corner!