Bondo comes to the Rescue !

When it comes to repair work on painted woodwork or trim work around the home, the best inexpensive product I've found is 'Bondo'. I originally used this as an automotive car body filler years ago for small dents, or minor repairs on my vehicles back in England.
It carves and sands nicely, accepts paint well, and because it is inurt, it doesn't expand and contract in humid conditions. When I was renovating an old Victorian house in Mansfield, Ohio, I used it extensively for the fireplace mantle surrounds; the proportions of hardner to resin filler, I used, were roughly one 'golf ball' of resin filler, to one large 'garden pea' of hardner.