Called Atlantic Enterprises

I phoned the nice folks at Atlantic just now, and explained the situation with the rack. I got a very fast call back from Thomas in their tech department. He talked me through what I needed to do to fix the play. Basically, I'll just unscrew the rod and add some more shims. They will be sending the required parts, including one of two lock plates I'll need. The second lock plate is no longer available, so I have to be careful with the existing one so it can be reused. I also got a follow-up call from Thomas emphasizing that I need to use red (and only red) locktite when reassembling the rod. Then another follow up call confirming my mailing address. Great customer service!