I've been trolling eBay for some time now, without finding any good case at all for the first gen. Padfone. Instead i started looking for phones that were similar in size and rear cam position, and i came up with the Samsung Galaxy SII, as the closest reference.
Today the Samsung case arrived, and i i had the case done within minutes. I used a sharp knife to gently get the Samsung back piece off, cut out a little extra for the Padfone speaker and LED. Then i just glued the Padfone case on, and applied pressure for a while, until the glue had dried.
Now i have my very own custom made Padfone 1 wallet case.