Try good old Brasso, good stuff y'know.

Try Autosol and apply with one of those green plasticky pan scrubbers.![]()
Give it enough stick and they'll go blue![]()

Assuming I want blue. But I quite like the silver. Someone must ride a Harley in this Parish. There's more stainless on those than Wiggins's trophy cabinet.
I thought the headers were chrome not steel. This would explain why Optiglanz wouldn't shift it. Getting rid of the discolouration requires some serious effort but can be done. You will need a drill with a hard and soft buff with the medium (red) and final (blue) polishes. You can get this kit for about £20 from Halfords. Don't use the hard sizel attachment on chro,e though....it will just scratch it.
I know this works as i polished up my TC last weekend.
Chrome plated stainless.
Ok with a little research 'autosol' seems to be the stuff I need for tarnished chrome. Halfords sells that.
Get an old T shirt, and cut it into long strips. Cover the headers in Autosol, then wrap the T shirt round, then grab each end of the T shirt strips and pull each end (not at the same time!).
damhik