Don't think you can buy them separately, as as they're crimped on (I found that out too) they must not be replaceable......I managed to polish mine up, and they haven't corroded yet!
The last set I saw on eBay went for over £200........which is a bit much when you see how much Nat wants for a brand new set.......you could try a set off an SS if you can get some from a later crash damaged bike, might be possible to make something?
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