New old stock lenses come up on e-bay quite often and are relitavely cheap. £20 ish.
New old stock chrome surrounds are rare and do occasionally come up for sale but are big money....The last pair i saw fetched over £150 and the auction still had time to go.
It is possible to have yours re-chromed but again, its not that cheap, i got quoted around £60 to have the pair of mine done and there is no guarantee how well they will turn out.
I have spare a rear lamp unit, on which the original chrome surround is excellent (probably the best you will find 2nd hand,) with just very faint patina markings, but no pitting,and shines lovely, but the lens has a couple of faint 'pressure cracks'.
See how you get on with the bay of 'e', they are out there, but how deep is your pocket??