Well I got around to doing this up today.
I did it more or less like my drawing, although I pulled it in tight against the engine.
I took some photos with my iPod touch, so they are a bit crap but just thought I'd show what I'd done.
I'll mount it back on my bike tomorrow and see how it goes lol..
I also had a problem with the exhaust, the bolt that holds the end cap on broke off (actually fell off while I was riding and gave me a flat tire
I Welded it together with a couple of good tack welds so that's not gonna happen again lol.