[knotty panda]

Magnetic clasps are an option as Miki's have sterling clasps. Sometimes there are health considerations with magnets though. Toggles are an acceptable substitute. With Miki's you should never replace a Miki clasp with a clasp which is not a Miki. And unfortunately, the only place to get a Miki clasp is at Miki's. When the clasp and pearls are separated, the pearls no longer have any value. Why? Because Miki can't tell the difference between their pearls and anyone else's pearls. A fact that is touted on this forum constantly and borne out by how Tiffany and Miki appraise their pearls -- by their clasps.

Personally, I would restring the piece with the original Miki clasp and always have a loving daughter, son, husband, granddaughter, friend, put the piece on. You get the picture. A nice tradition of sharing an intimate moment helping grandma. I know, I'm such a softie.

However, if they insist on you restringing it rather than returning it to Miki for restringing, by all means make sure you impress upon them that the clasp should be kept in a safe place. Regardless of how this forum feels about PPBs, I'm sure your client believes her Miki's very valuable. You have an obligation to protect her interests.