That said, I like this, but it's still not quite right. I need to made it with a second level of card pockets and a little longer than the 13" rectangle to accomodate that - the original sizing came from the Crazy Mom Quilts Checkbook Tutorial.
Because these were just quilting cottons, I added fusible fleece to the back of the lining fabric to give it a little more strength. And now, the pictures. I didn't take any while I was making it - in total it only took about half an hour.
Folded and closed. I ironed the fold, but for future ones, I think a magnetic snap will be in order.
Open, you can see the three card slots I made and the other side for cash.
This one lets you see that the lining is the inverse of the outside - white with red polka dots.