A new found red horizontal Gold Dust Club was reported that has the Holiday Inn logo at the right on the reverse. Turns out the re are two variations of the 6th issue horizontal cards with 3 logos on the back. The first set has a Silver Dollar logo at the right while the second set has a Holiday Inn logo at the right. I've split the 6th issue listings into 6a and 6b issues to separate the two sets of cards without having to renumber the following issues.

Here's a scan of the new found red card with the Holiday Inn logo on the back...