I had a go at upgrading and maybe I am not understanding correctly the instructions:
This is saying use the two configure.php from your old site with the new/merged fileset. But the 1.5 configure.php are different structurally so surely it should say copy the configures from the 1.5 demo site you have been playing with and edit the paths and db details to point to the merged site and old db copy that is to be upgraded?If your /zen_new folder doesn't have "/includes/configure.php" and "/admin/includes/configure.php" files, copy them from your old store folder.
EDIT your "/zen_new/includes/configure.php" file and ensure that your DATABASE_NAME matches your NEW database. Also verify database username and password in case that information has changed. Save this file, and be sure to upload it as part of the next step. Repeat for the /admin/includes/configure.php file as well:
Bookmarks