Hi Mick, welcome here,
simple answer is to get somebody else to weld it. I guess the guy tried to weld it in position and that is /can always be a problem with access. If it appears to be a weak point then strengthen it up with another piece welded to it
Agree that welding can be problematic as many attempted welds are simply surface weld joints. It requires tacking in the correct position then grinding and deep welding to restore the joint full strength again or better.
So far since I learned to deep weld I can restore most item back to the same dimensions as they had originally. Even then if replacement parts are available they generally a better option especially for adjustable versions.
Just to note here that I have never a Rover Rancher or its ipl so I have idea of the parts that were welded but any confident welder can weld just about anything; just got know how. I personally have had to redo a lot DIYers welds that were poorly done.