Just came across a new variation of the 5th issue Affinity Gaming APlay Club with the Silver Club. On the originally listed card, the large "Affinity Gaming" on the back over the casino names starts to the left of "Nevada" below. On the new found card the Nevada listings were moved slightly left so it's aligned with the Affinity above, creating more space between the Nevada and Missouri casino names. That makes the length of the bottom line change from 65mm wide to 67mm wide.
Here's scans of the original card and the new variation.