I know this thread was started a long time ago - but today I spotted a purse made with the tabs and had to search the internet to find out how to make one of my own.  I came across your post and let me say, it's amazing. I love your bag!  I read a post here where someone else found directions on how to make the stitch: http://www.mosaicminds.net/slapdash_independence?x=69&y=63 and thought I would add one that I found that I think is helpful too.  It's for a belt, but it gave me a clear idea on how to use that to make it and add to it until I could form a purse.  http://www.ehow.com/how_4839559_pop-tab-belt.html

Thanks so much for taking the time to share your project with the rest of us.