Thanks for looking and for your comments. When I was working in Photoshop, the difference seemed greater and the first one looked somehow flat, but looking at them here, I now agree with all of you.
Taking a second photo adds to the
work, but the alignment is easy as long as I don't have to touch the setup in between shots; I can alter the camera settings from my PC. I will write up the details of the method shortly.
To add to the variety of methods, here's the photo I was trying to improve on, taken a couple of years ago. The darker tone results from using a shorter exposure to try to cut down the highlights. I can do that better now; I learn more quirks of photoshopping every year.
Bill