The repair should be fairly straight forward.
1. Remove both standards from the rails.
2. Remove the focus track and tripod socket.
3. Fill an ink refill syringe ( ) with a good quality wood glue ( ).
4. Spread the split with a #0 or #1 slot screwdriver just enough to inject the glue into the crack the full width and length of the crack.
5. Clamp with a spring clamp such as a Jorgensen 3203 (readily available at hardware stores). 2 or 3 clamps may be needed depending on the length of the crack.
6. Wipe excess glue off with a damp cloth or sponge.
7. Let cure for at least as long as the glue instructions say.
8. Reassemble the camera.