As a woodworker, I would probably not use wood glue. I would use a good two part marine epoxy. I would use it and clamp it for 24 hours. I would use that time to contact Marlin about a new stoch.
In the meantime I would shoot it without reservation. That epoxy is good stuff.

If that were my gun, I would write that story down and insert it in the stock. Just in case something ever happens and it leaves the family. Stories like that need to survive. Sort of lets future generations know what their predecessors were made of. Your mother was one of a kind. Earl don't sound t...