Is This PVC Damage, Or Normal Old Silver? (Argentina 1882 50 Cents)

PVC damage can often be greenish or slimy and may cover an entire rim plus the high spots

That doesn't appear to by PVC damage. When PVC turns into the green goop it is in it's destructive stage, the PVC leeches onto the surface of a coin and becomes hydrochloride acid (I'm no chemist so I may be describing this process entirely wrong). That in turn etches the surface of the metal on the coin, causing pits and eaten away surfaces. Acetone should remove any of the organic contaminants including PVC on the surface with a rinse or soak, then re-rinse with some fresh acetone to remove any particles (for stubborn areas I will lightly roll a cotton swab over the area affected (only on circulated coins) never on proof coins. The re-rinse with clean acetone helps to insure the coin is clean, leave out a minute to dry, acetone evaporates quickly.

Of course warning acetone is extremely flammable so no open flames around, no smoking and use in a well ventilated area only. Outside in shade is best. Sunlight acetone and copper are not compatible, keep your coins and work away from direct sunlight so as not to cause any discoloring, silver, and gold do not have that same issue with acetone. Xylene can be used in place of acetone, I don't like it as much as it is a known cancer causing agent, but otherwise the properties are similar as are the effects on coins.

Here are a few older threads on coin cleaning/conservation here at CCF:

Copper coins - http://goccf.com/t/404457

Acetone vs. Xylene - http://goccf.com/t/398235&whichpage=2#3412791

Distilled Water? NOPE - http://goccf.com/t/398235

Acetone general - http://goccf.com/t/174056

To be fair, nothing is going to remove the damage caused by PVC. The damage is pitting and etching into the metal, so PVC damage is far beyond any type of "fixing." Acetone will remove PVC slime and sludge and if done before the etching occurs, it is perfectly fine and safe, acetone removes almost all of an organic material like PVC residue, glue, adhesive, etc. from a coin's surface, it doesn't cause damage (that I've ever seen) and doesn't change the coins color nor affect 99.90% of natural toning or patina.

Not a fan of any of the lighter fluids as they contain Naptha, benzene and other known cancer causing chemicals. see this safety sheet on Zippo lighter fluid (PDF file).

https://ilrc.ucf.edu/documents/ILRC...%20Fluid.pdf

One thing I will say on acetone, is it can certainly cause a drying out of a coin - especially copper, I treat mine with a touch of verdi-care or CARE (old Blue Ribbon) when done. Granted I am talking about only circulated on proof coins. All of my Two Cent coins get treated with acetone after I purchase them. After 30 years none of them show any ill effects from it, of course they are stored properly in a low light, low humidity controlled environment.

Westcoin: I find lighter fluid delivers much better results than Acetone, and is MUCH more color-safe. Major Stamp auction houses use lighter fluid to check for watermarks. They do NOT use Acetone for a reason, or two, or three... I used it exclusively to restore some old Baseball Aluminum-bezeled pog premiums (1909-12), and received grades in excess of 9 on just about all of them. Impossible to do with Acetone...

You don't use acetone on stamps because acetone is very very good at dissolving things, including the ink used to print stamps with. An acetone-washed stamp is likely to come back as a blank piece of paper. That's very very bad for stamps, but it's exactly what you want for goo stuck on coins.

Of course, if you have need for both cleaning coins and watermarking stamps, then the lighter fluid is probably good enough as a dual-purpose solvent. No need to have two separate bottles of dangerously flammable liquid sitting around the house, when just the one will work just as well.