Simple & does the job.
To make changes (eg. RTL [Hebrew/Arabic] setup, page size, etc.), you must first move the workflow from root to your user account:
From /Library/Services/Create Booklet.workflow
To ~/Library/Services/Create Booklet.workflow
To keep the original and add a second menu item with your changes (eg. "Create Booklet" & "Create RTL Booklet"), open the original and make your changes.
When you press file->save, Automator offers to save as a duplicate, which it saves in ~/
The reason the script stores itself in /Library instead of ~/Library is so that the booklet will be for all users, but it can confuse users that do not understand the restrictions on editing that Apple imposes.