Hmmm, I thought it might be possible to use aluminium brazing or somethingto cover the pantographed side and sand/polish it back but perhaps not. Thanks for the offer canopus but I'll see what I can do with the ones I've got. They were less than $10 and already corrupted by the previous owner so I don't feel too bad about altering them further. I'm going to try reversing them so that the defaced side will be facing downwards. It shouldn't bother me to much if I'm not looking at it every day.