OK, so as I mentioned earlier in this post I spoke with Nigel on this topic, and agreed for me to visit their garage to have the rusty section removed. In discussions I also decided to have the centre silencer replaced [for a small fee] in an attempt to remove the drone I was experiencing with the exhaust as was.
Over the phone Nigel was nothing but helpful, he totally understood my position and was keen to rectify the issue, which given the age of my system he would have been totally within his rights to refuse.
I drove over to his base on Tuesday, which was a pretty lengthy return trip for one day [7hrs], but at least I would experience the improvements I hoped for on the return. Upon arrival, his team were spot on and even gave me a mini tour of their new premises [a work in progress], and had a great chat with Nigel about his past and future plans over a coffee. All this whilst his team immediately took another car off the ramps to start work on mine, but not before walking me through the planned work.
About 90mins later they'd finished and showed me the work before dropping the car, which included a new silencer, a new section to replace the rusty flange and all braces had been replaced for newer design. It did look a bit 'mix and match', but I could not have expected anything more than I received, and the quality of work was top notch.
The rust was not a performance issue, but more aesthetics and durability, but the new silencer has made all the difference. With the reduced sound it has somehow made my cars performance more accessible / unnoticeable as it comes without the drama of the old exhaust.
All in all I was nothing but impressed by all in BCS and they certainly know their stuff, and I highly recommend their service and products.