A friend advised that the spurious bracket was a generic item included in quite a few David Andrews Kits to aid in fixing the exhaust injector casting. in the end I elected to do without it and drilled and tapped the main pipe. I will probably do the same to the flat on top of the bracket too because I have fixed one problem and create another – where it needs to sit there is nothing above it to screw it to. I will add a small plate under the main plates that fit under the cab to extend it and allow me to fix to it.
Hopefully it will make sense when I have done it and taken photos. I have also added the missing control rod on top of the universal joint.