I found your apron on Ebay for $8.95 including shipping and the add says the instructions are included just in case.
I also found this picture of a different apron of DM's, that shows the squares made into pot holders and also how the binding/strings are attached. It might solidify in your mind how your pattern should go together?
http://www.mallcarts.com/images/ttw/dma2.jpg
Good Luck!