This coin appears to be much better under a coat of flaking lacquer than it currently appears, even with the hole. Is there a relatively safe way to remove very old lacquer? This might be a Bradthad special. [/QUOTE]
The value of the coins has been depleted dramatically by the hole and the lacker preserving it. How did you come across this coin, it almost looks like someone in the past used it as a necklace or button. Maybe leave it alone and sell it to a button/ clothing collector they may pay just a bit more as it is a coin. But if you really want to remove lacquer 100% acetone will do the trick. It will also eat away at the coin leaving a porous surface, to prevent this, since the coin is already worn, try putting it on a 100% cotton cloth and gently working off the lacquer. I use to help my friend build guitars, lacquer is my specialty
If you says so RLM I will believe it I never clean coins so I know what I know based of what Acetone does.
Acetone affects organics and is is descent solvent. It is pretty much inert to metals. The only way I know of it affecting metals is when it oxidizes with age and forms an acid which will affect copper. If you search hard enough you should be able to find a reference to the chemical reactions I am referring to.