Hi, everyone. So I have a three panel interior door (not hollow core) at the top of the basement stairs that has a hole cut into the bottom panel. I assume that it was for a cat to access the basement at some point.

I want to fix this without having to buy a new door. Any ideas? I'd say the way to go would be to pull out the panel and replace it but it doesn't look like that's possible as the bevel that surrounds each of the panels isn't a piece of molding. It's cut into the rails and stiles that surround the panel.....

The panel is about a 1/4" thick. Is there a way I can repair this working from the back? Another thin panel or piece of wood on top of it then something that fills out the hole, glued to that panel and finished with joint compound/sanding?

Appreciate any thoughts or advice. Thanks!