You're right, I didn't delete that copy of the scenery.cfg file.
But it's not where you indicated, if only because there isn't an 'All Users' folder anywhere. I've found two copies of it and two shortcuts to the file and all seem to be the default version, at least I think so.
I did use the Scenery Library feature to remove my Addon Scenery before I filed them away on another partition.
Anyway, I deleted the scenery.cfg file that Steam installed and copied the one on the C: drive across and IT WORKS!
I've got real California and Nevada back and I've flown in and out of LAX and out to Catalina just to show myself that it's all working.
Thanks to all of you who've tried to help me get out of craziness, I'm VERY thankful.
Regards
Kit
PS I'll add all the other sceneries item by item and check after every one.