Hey, Dale!
What is your wall construction? I use plywood walls (with cutouts and insulation) and have put racks on the last couple of my personal teardrops:

What you don't see in this pic is the 7-gallon propane tank (full) and the portable propane fire-pit that had already been unloaded. I've also carried a 17' Grumman aluminum canoe
on top of a similar load, all with no problems!

This pic shows the simple mounting system ... the racks are removable, and the stainless steel bolts that hold the rain-gutter sections to the walls have only 1-1/2" ss washers against the inside walls.
I've never weighed all the stuff I've put in that basket and on the racks ... all I can tell you is that my back always hurt after loading or unloading it ...

...!
Check out a couple of bicycle or canoe/kayak stores in your area ... I'm sure they have something like our Yakima or Thule brand racks and similar mounting systems (though most of those don't fit on the straight side walls of a teardrop). If you can't find anything similar, I could probably sell you a set of towers and mounting rails if you could source some 1" steel tubing locally (remember, I'm limited to a maximum of 42" length in shipping to Oz ...

...). Just let me know if I can help!
Good Luck, and as always ...
CHEERS!
Celebrating
Retirement after over
32 Years of Building, Promoting, Supporting, Supplying, Living the Lifestyle, and Loving
Teardrop Trailers!"Life Moves a Little Slower When You're On Teardrop Time"The nature of Life, itself, is change ...
"Those who matter, don't mind, and those who mind, don't matter." 