Thanks. Unfortunately, I haven't been able to figure out who built it. I went really slow with the paint removal (dark blue non-original top coat, light blue original paint, then a layer of clay-red primer) but it didn't give any additional clues. I thought perhaps it was French, but the threading is ISO.

The do-dad on the top tube is a quick-release for the rear brake. It's got a bit of chrome on the end of it, which is why I taped it in preparation for painting.