Ok , Got it working.
Want I did was, stopped trying to install the aforementioned scenery and picked a different one.
File savannahgeorgiausa_dlffsx by Dan French.
Unzipped it and placed the Savannah folder containing the scenery and texture subfolders in FSX's , addon scenry folder.
Started the sim and clicked on settings
Clicked the scenery library button from the options on the right side of the window
Clicked on add area from the options located on the right side of the window
That causes the "select scenery directory" window browser to pop up.
I navigated to the addon folder in FSX's root directory where I placed the Savannah parent folder.
I clicked on the ""open area under the files "" you pointed out in your graphic.... nowt a thing happened.
I Doubleclicked the Savannah folder and saw the subfolders
I clicked on the open space area As you directed
The "select scenery directory" browser window disappeared and I saw the added savannah airport in the list.
The addon folder has been renamed back to addon Scenery...
Perhaps I'll have another look at the read me for KFHR
Thanks Gents.
thank you so very much
Joe