OK, I've made one from memory. Here's how to do it using a couple of rolex cards and wool. Get that working first before you try leather and gold chains!

Lay the two cards side by side, touching long edges. Make a cross on the left hand card long enough to cross the entire card and overlap the other about an inch or so. Fix top and bottom parts on the FRONT LEFT of the left hand card so that it naturally falls to the LEFT of the left hand hard, and then on the BACK LEFT of the right hand card.

Next put the two horizontals in place, fixing them to the RIGHT of the RIGHT hand card, so they naturally fall to the RIGHT, then pull then over the front of the right hand card and fix then to the BACK RIGHT of the left hand card.

You may then want to put additional cards in place to hide all the sticky tape, etc, so that all that is visible is the two sides, the crossed tape and the stright tape.

If you have followed all of this correctly, you should now be able to open the wallet from either the front or rear edge.