Does the axle need to be centered in the wheel wells of the trailer. They don't look very big from you picture but I'm not there.
If the axle is set on a "slider" you simply lock the trailer brake and use the tow rig to move the camper on top of it. Then lock it in place with what ever system you choose.
Speski OffRoad LTD, Cargo Solutions for Toyota 4x4's http://www.SpeskiOffRoad.com
"80 series, with a fridge"
1976 FJ40, Project with little progress.
2004 Starcraft 10RT