Here is more info on what happened.
In the process of restoring databases several times, the "Enforce Password Policy" got re-checked.
Well, what was happening was the user had too short a password. All I know is the issue , duplicated by adding the user to the dev site, disappeared after trying to reset the password and getting length issues, etc and the finally unchecking that box. At that point, the Dev site worked.
The database got removed and replaced but the Login, created in the Security area of course didn't get removed and replaced. Anyhow, unchecking the box, resetting the password and putting this into the Dev web config, it works.
Now I'm getting the domain can't be found for the production site but ... that's improvement from where it was.
Another gotcha on UserId is, it has to be spaced to User Id. That was another issue I didn't expect.
Should be able to resolve this now.