I used a drill fitted with a varnish and paint remover disc (flexible) to remove the pitted chrome. I would have liked to remove the pipes but was advised the head studs would probably shear requiring the cylinders to be removed.
Once the chrome was removed I used an old Cetem polishing kit with buffing wheels and resin to buff the stainless and remove the fine scratches. They have since blued slightly but so much better than they were at no cost!
Hardest part was finding out that it was definitely chrome on stainless.