I'd recommend you to wait until tomorrow and take pictures in broad daylight. That garage with dim lighting is probably not going to deliver the best pictures. Capturing something as small and shallow as a worm track can be tricky. Set the camera in macro mode (the button with the small flower icon).
A worm track across the back is probably difficult to repair. It is THE place where a splinter can lift. You can try patching it with sinew or flax fibers, but just filling it with glue and sawdust is not a structural solution on the back of the bow. It would be on the belly, though. Chasing down another ring would be the best solution, as long as you can keep enough wood.
