Need exhaust back box mod doing - north shropshire

[worton]

I've recently purchased a fantastic e86 from another forum member on here (will get round to doing a hello post at some point!) and im looking at changing the back box. i've just purchased a stock box from another member with the intention of getting it modified to give a bit of a better stock sound and wondered if anyone knows of anywhere near north shropshire/telford/stoke way that would modify the box for me?

thanks

chris