You obviously did not take up my suggestion of contacting Marque restore in Coventry, if you had they would have informed you that while they do not undertake repairs they do employ a small company that will repair these items.
I have had three sets of rear bumpers repaired due to corrosion and they come back looking as new.
They have also re-chromed several complete sets for me.
The only downside is like all re-chrome companies it takes time.