This post on the WordPress support forums seems to have helped me resolve the bad Dashboard display, although I can’t point to a specific issue.

I changed the name of my plug-ins folder (renamed from “plugins” to “plugins_old”), logged out and logged into the dashboard and forced a reload of the pages.  Dashboard looked normal.  I then turned on the plug-ins one by one to see if I could identify a specific one that was causing a problem.  Alas, plug-ins back on and the problem did not come back.  So, the problem is fixed, but the source of the problem is not identified.

I’ll roll this through the other sites and see if I can find out more, but for now dashboard works fine which is all I care about right now.  Too busy to spend time exploring.