There is a place in hillington called peacock and trelfa a think. (Excuse the spelling) Had some classic car bits done there - bumper, grill and bumper overriders - very good results. (mega bling

)
You MUST prepare the item first, or the results are crap (peals off after a month or two.)
prepare - as in wire brush the rocker back to bare metal! hard work unless you have an electric drill and a rotating wire brush

then its just time and no effort.
I know a chap who could not be arsed and didnt prepare it at all handed his bumper in came out nice and shiny, but the GB sticker remains were still visable on the chrome!
So he hates that company!
So if you are willing to put some effort in they are good.