Dennis-
Thanks. That had been my initial thought and I spent over an hour yesterday trying to get it to work. My biggest problem is that because the holes in the roti bracket are so much larger than the standoffs on the rear mounting studs the roti bracket tends to slip over the standoffs and so the roti bracket just rattles around behind the side table bracket and never gets tight.
Based on your assurance that it works, I went and tried again today and managed to get it on by keeping downward pressure on the roti bracket as I tightened to force it's to just catch on the standoffs - it's tight but seems precarious since if the rote bracket moves at all it'll slip over the standoff again. I think I just need to replace the standoff with something larger diameter (stack of washers?).
Thanks,
Steve