Leon from the owners club recommend using Pugz Polishing... I have now used him twice, once for my manifold and again for my link pipe.
Here is it before..
Here it is after Pugs have finished with it..
Would highly recommend.. Below is a link to their facebook page where you can see examples of their work and contact details. Don't forgot to mention me and Leon.
https://www.facebook.com/Pugz-polishing-305230949574161/timeline/