Firstly, let me apologize for the crappy indoor photos. It’s raining like crazy here in Texas. I got a great deal on this ring that I purchased online. Howver, it’s not quite what I imagined when I received it on person. It’s heavily stabilized and backed, and the stone is very thin. So I’m gonna sell it. My question is, there looks like what appears silver nail polish on the edge of the stone. Can I safely remove the polish with acetone? Is there any chance that this silver strip is a part of the stone backing?
Hey Bree! Raining here too in the Hill country; like crazy! Must say that I do like seeing the Pedernales river running top full though! 
I have a feeling you are dead right on this one. Flog it. Looks like it may have been a replacement that just didn’t fit at all. Looks very high on the bezel from your photos. It looks like it may have been an uneven cab. That silvery part looks like a filler that was then molded to the Devcon. Normally you wouldn’t see the Devcon in a properly sized and set cab. I would be really cautious about using the Acetone in it. Maybe go after it with a Q-tip in a small area and keep water close by in case.
I have seen a few cabs with that silvery filler in the last three or four years, and it never turned out great for me. I run from it now. That and I carry a rare earth magnet when I buy. It is invaluable these days! Devcon and Turquoise are non magnetic, as well as silver. So if you catch an attraction on something that is the first sign something is wrong. This has helped me greatly when buying cabs as well. Turns out that an unscrupulous practice from years ago is really making a come back regarding Turquoise cabs. Many a Lapidary these days are adding iron filings to the Devcon to give some extra carat weight. It blends into brown and black Devcon so well it is invisible. Same stuff you would get running a magnet through sand. I digress…What you might think about is trying to remove it from the setting and find another cab.Something a bit thinner. A bit of trouble I know, but may be worth the effort if it is a signed piece.
Think I would wet with water and gently scrape away with fingernail or wood toothpick before I used acetone. If it is a part of the backing might use a knife gently to get a clean cut at setting.