I finally finished it! As described previously, I started off with a painting gathering dust in a thrift shop and changed the mood. Besides doing the ultimate day-for-night rework, I also wrapped the matte in black satin and repainted the frame. The disassembly, and subsequent reassembly, involved lots of pointy things. I’m glad the painted result wasn’t too precious to me, because there were some awful things done to it (that required a little repaint, too!) to re-attach the whole thing.
Getting the headless horseman to look reasonable was not easy. I was happy with the result of one minute of sketching, but getting the painted part to look right was not nearly so quick nor satisfying. To figure out what should happen with the flaming pumpkin, I set up a tealight in a black box to stare at it and its reflected flickering. I’m pretty happy with the end result, though I think I was too effective at changing the mood. It’s so gloomy that I’m not sure I can find an appropriate spot to hang it up on the wall.