Greetings C. Student!
I kept your thread in mind as I was sorting through my photos as I was sure that I had a series of photos take at the WBCCI International Rally in Dayton, Ohio on June 30, 1999. These digital photos were taken with a Sony FD90 camera so aren't up to today's standards for resolution.
The trailer involved was a 1948
Liner (I believe that it was 21 or 22 feet). The LP tanks were not on the tongue, the water tank was empty, and some of the interior was out for restoration. The trailer and bicycle were owned by Clyde Wagoner who had led the Wagon Wheels Caravan into the Rally. The bicycle was a montain bicycle with a trailer brake controller and hitch added.
The participants quickly learned that getting started was nearly the trickiest part of the experience -- any wobble in the bicycle translated to "sway" in the trailer. Keeping the rig in a straight line required intense concentration. Stopping the trailer required a steady hand on the brake controller. As can be seen in a couple of the photos some assistance helped in getting the rig underway.