If the crack is openable it can easily be fixed. Pry it open use wedges if needed, and use a toothpicj to drizzle in epoxy glue, I prefer DevCon. Use an air blow gun to blow the epoxy to the ends of the crack. Clamp and/or use surgical tubing to close the crack back up and all will be well. If the finish is good you'll need to cover the stock with masking tape to keep the epoxy from destroying the finish. Just leave the area around the crack exposed. A very light pass with steel wool or 220 grit paper and a bit of finish will tune it up. If it's a poly finish it's much more difficult to patch. If the crack can't be opened enough it will have to be injected. Drill imtersecting hole, less than 1/8 inch, thru the crack. This has to be done in several places and such that the entries can't be seen with the metal assembled. Drip the mixed epoxy into the hole and apply a blow gun. the air pressure will force the epoxy back into the cracks smallest recesses. Be careful and try not to use too much pressure as it is possible to blow chunks of wood from the stock at the cracks lip. Use only the slow setting epoxy for the enhanced working time and the improved strength over the 5 mionute kind..