LT Pannier Buckles

Hi all,

Spent a good few hours cleaning my 66 Reg LT yesterday and I was somewhat annoyed to see the buckles on the panniers were very dull and surface pitted.

I have previously given them a light rub over with a soft cloth each time I've cleaned the bike but this dulling & pitting seems to have appeared in the last couple of weeks.

So, question, has anyone else had this problem & if so, other than re-polishing & then lacquering them, what is the best way to keep them looking nice.