Buttstock endplate moulding damaged

[t3dd13]

I have a question for you guys. The butt plate moulding on the stock is broken so the butt plate moves a lot when screwed on. What's the best way to fix it. See attached picture for condition. I stripped the rifle of it's finish already because when I bought the previous owner did a really really bad varnish job (hair and fingerprints all over stock, varnish on the action which I mistook for rust originally)

In your opinion, what's the best way to fix this and so I can re-attached the buttplate without it moving around?

 

[guntech]

Pull the broken wood out, apply wood glue to broken surfaces, tap it back in place, wipe away excess glue, let the glue set up for a couple of hours, assemble.

 

[Silvertip13]

Clean the effected wood first with acetone and let dry before doing what gun tech said