Nevermind. I was able to find what Ed added to my old single.php to change the default sidebar setting to right sidebars for existing / imported posts.
He added:
if ($sidebar_config == "") {
$sidebar_config = "right-sidebar";
}
if ($right_sidebar == “”) {
$right_sidebar = “Sidebar-1”;
}
Right before the section starting with:
$page_wrap_class = '';
It would awesome if an option could be added in future updates that would let the site owner choose the default when it’s being implemented with existing posts. Full width just doesn’t make sense for most blog post pages.