Thanks again everyone. Photos are spot on Mick gonna try that tomorrow, will just bolt ball joint straight onto plate on axle then go through your process. While I’ve been waiting for awnsers I managed to get a wire threaded throughout chassis for harness. Easier then I thought, I suppose the hard bit will be pulling the harness through.
Most people will advise against threading the loom through a galv chassis for fear of damaging the loom.
When I lined mine up with the extension, it moved the chassis relative to the axle, so don’t be surprised if you move yours too.