Think your problem will be the difference between a leafer and coiler axle Steve.
I'm sure there are references somewhere on all the Frontera axles, basically it's spline count and shaft diameter.
If you consider an axle swap, your problem will be the leaf hangers etc. with the coil spring mountings.
When you bought the Lokka, was there an option to quote your VIN number to Lokka as a cross reference check. You might have a bit of a leg to stand on to present your case to Lokka on an exchange.