There's Younger Son, crouched happily in front of the shiny new wood heater. I'm pleased to say the thing works a treat. Heats up faster than the old kachelofen, though without the brick box around it, the heat also fades faster. But it burns very efficiently, and the glass front lets you watch the fire, which is very nice.
I've still got to clean up the back wall, maybe add a few more slates to frame the brick mantle behind... clean up the grouting and the seams (I ran out of grout) down the front there. But it works, and one can hardly ask for better.