MDW,
You may want to check the www.simpletractors.com site. If I recall correctly, they have a link to most of the manuals (available in *.pdf files) from the Simplicity website. If you can't find it, I'd recommend posting the question in the discussion board of the simpletractors site (goto the clubhouse) as the 712 is a popular unit and the folks there are quite knowledgeable of the AC/Simplicity L&G tractors..
Mike