Thanks for your input to my buzzing problem. The good news is I have "Fixed" it! I was going to shield all of the cavities with copper tape however, I decided to re check all of my solder points for about the 6th time before commencing the shielding process.
What I found was that the earth wire on the input jack is made up of many FINE wire filaments and a couple of them had broken (very difficult to see) and were touching the active wire on the jack.
Thankfully the problem is solved and the guitar sounds great (at the moment).