If you have any sheet Copper metal chassis parts you want clear lacquer coating then I can heartily recommend this Company:
Vernon Moss (Electroplating) Limited
Churchfields Works
Churchfields Road
Brighouse
HD6 1DH
Tel: 01484 710153
I sent them 3-copper sheet metal chassis parts I had made for my 6EM7 amp build and although I had initially buffed the sheets to my best ability there was still some minor scratches I could not get out.
I left the final fishing to them and they suggested a satin finish with the electrophoretic lacquer coating to retain it's nice finish.
They are very easy to talk to and discuss your requirements.
I must say the finished result looks great without the hint of any surface scratches. Down to the satin finish I guess.
I'll post a new thread of the amp with piccies when it's finished.