I worked on this some more, added a couple of dark glazes for the background, and felt pretty satisfied. Then I brought the painting downstairs and asked my dear husband what he thought. His first comment was that it was "pretty good." Then he added, "but it doesn't look like you much."
It happens. You work and work, fiddling with highlights, shadows, color choices, and an offhand comment makes you realize a project's flaws in a moment. After I photographed and posted the painting it occurred to me that there is something rather cock-eyed about the mouth, and there are places where the values are just to dark. One the other hand, I think this is the best portrait I've painted. I like the sunny highlight at the bottoms of the face, and I think I handled the jacket effectively. Perhaps I'll let the painting rest for a few days before I decide if I want to play with it more. Maybe it's just time to move on.
Update - I did fiddle with the mouth (wider) and left eye (lower), and while the paper is now officially overworked, the face looks better. Now I'm wondering if the top of the hat is too white.