Hi Jim,
Assume that you have layout called 'default2' (simply duplicated the file /tpls/default.php) so you have /tpls/default2.php
Now you want to customize the mainbody block for this 'default2' layout, you can duplicate the folder /tpls/block/mainbody.php to to have a new one: /tpls/block/mainbody2.php
Create a new folder: /tpls/block/mainbody2/ + copy all files inside /tpls/block/mainbody/ folder to the new folder
In the file: /tpls/block/mainbody2.php, make sure that you update the path of these blocks to the 'mainbody2' folder
// detect layout
if ($sidebar1 && $sidebar2) {
$this->loadBlock('mainbody/two-sidebar', array('sidebar1' => $sidebar1, 'sidebar2' => $sidebar2));
} elseif ($sidebar1) {
$this->loadBlock('mainbody/one-sidebar-left', array('sidebar' => $sidebar1));
} elseif ($sidebar2) {
$this->loadBlock('mainbody/one-sidebar-right', array('sidebar' => $sidebar2));
} else {
$this->loadBlock('mainbody/no-sidebar');
}
Then edit layout here, it will not affect the default layout.
Regards