It seems that I was the cause for the derailment from the original question, so the least I can do is answer it with my thoughts.

For me, whenever something is in a state or context that feels like there is a story attached to it, I will not alter it.
However if something is made purely for sales, or ease of travel, I do not have any hesitation. This is for example the case for me with most strands of trade beads.

One bead that had me think for a while as to what to do, was this Warring States Bead. I bought in China, one day after Redmountain (who I met in Beijing) had warned me about Warring States beads often having the eyes repaired or faked.

Even though I was warned, I did not see what was wrong with this bead until after I bought it. I believe it is an original Warring States bead, but the yellow eyes are fake. They are made of polymer clay and are glued on. At first I wanted to take them off. But I have decided that this is now a bead with a story that is interesting to be kept as is.