Seems that Mike nailed the situation Mark, but it is also interesting to observe that Rogers was a bit all over the place locating mounts at a certain point in time. Even the picture Mike posted shows a catalog set-up with a swivo mount looking right at us that has no apparent purpose. I think it's also kind of interesting that the double tom mount on the left side is empty on one side. One would have thought they'd have put in a straight rod and a splash just to show the versatility of the mount. The 67-68 catalog was a piece of catalog perfection, but by 1972, even the catalog effort was getting lazy.
The pictured set I had a while back, which was from late 1968, is by no means the only one I've seen like it where the tom mount is one panel away from its normal position. You can see the Rogers script, and the tone control is just out of sight. This layout exposed the seam too, which is something they were very careful to avoid in the earlier days.