Thanks Balinor, for the suggestion about shutting down and restarting the browser, but I had thought of that and had tried it many times along with other processes in the effort to get, what I now know is the file "txt_welcome" to re-appear in webmaster mode when editing
http://befreetech.com/xcart/home.php.
Today I installed from scratch and built a dummy build of the software to learn that the file name I was seeking is "txt_welcome".
After using the language feature and editing that file, per your previous suggestion - I was able to enter webmaster mode, roll the cursor over that file which was now alive and well, and then edit it in wysiwyg mode, - make changes, and then see them appear at
http://befreetech.com/xcart/home.php.
Finally I could update them to the html catalog by deleting the old catalog and allowing it to generate "dynamically" from the source "home.php" page as edited.
I'm elated, and very thankful for your assistance, since the clues you gave me, helped me figure out how to solve this problem, as it's been nagging me for several months.