I built a 2 place stand up out of single couch trailer 4 years ago. It works great but I want something I can mount my beach cart on also. So I picked up this aluminum 3 rail motorcycle trailer this passed Sunday.
Went back to the shop tonight, I brought the skis with the old trailer and moved them to the new trailer, I'm really happy the way they fit and how low they are. Next, fab up some bow stops and figure out a way to mount my cart.
The old trailer is for sale. I built it 4 years ago, it has a locking coupler, matching spare, poly tongue box, new hub. Painted with a industrial epoxy paint. Asking $650....and sold in twenty minutes.... I guess I should have asked more!
In Australia, we have these racks available to mount (via u-bolts) to existing trailers. They're ideal for carrying large items like totes and marquees. Your trailer would be an ideal candidate as the outer chassis rails are clear of obstructions/fittings.