"Steaming stocks will only work if it's bare wood IIRC ..."
Not always.
One of the years I worked in a museum was working side by side with a funiture refinisher. I've seen him steam dents out alot .. and with the finish still on.
First time I saw him do it, I said about the same thing to him. His reply was that if you could look at the surface under a microscope, you'd see that the finish is all broken up in the dent. It's slow, and can sometimes stain certain woods like white oak, but it does work.
He used a tea kettle on an electric burner and proped up a rubber tube jammed in the spout so it pointed right at the dent and about a half inch away. He'd leave it like that for an hour or so checking occationally, then let it dry out overnight. Next day the dent would be gone. When it was compleatly dry, he'd then lightly wet sand with 600 grit, wipe it down, and go over it with padding laqueur.
Paul.