That sounds like very good advice, which, for the sake of my sanity, I will follow!
Thanks, Andy
BUT
If you do find out about changing the base path of the site do let me know, as it could come in handy for certain situations.
Placing the code as below in the manager/includes/config.inc.php file did cause modx to rewrite the automatically generated menus, but the second line did not work. I got the pages served up, as requested, with the desired url, but all links to MODx style sheets and functions were lost. I have included the last, commented out line, so that you can see where, in the file I had placed the code.
$base_url='http://www.lotwplantation.com/';
$base_path='/home/lotwplantation/www/www/modx/';
$site_url='http://www.lotwplantation.com/';
// automatically assign base_path and base_url