Do you remember I asked for advice on how to loosen painted-over screws? I'll forgive you if you don't — it was over a year ago.
The replies I got varied in their usefulness. I put the job, and the whole room, off for a year before I got back to it.
The screws in question were in the bit of wood over the window in the photo. In the end, I inserted a screwdriver in the slot in the screw head and whacked the screwdriver with a hammer a couple of times, while hoping I wouldn't break anything but the seal of paint around the screw.
I managed not to break anything but the deal of paint around the screw. When I tried to turn the screw, it actually moved. It must've been some sort of combination of technique (thanks, cousin Ian!) and HOP muscles that did the trick.