Did I Destroy This Coin's Value?

Make sure to give the second picture a different name. Otherwise, you will
replace the original.
Have you got the second photo under 100KB?
At times, the image uploader gets 'funky,' but waiting several minutes before
trying again usually does the trick.

As damage is already done document what steps you used.
Would make a great cautionary tale on the pitfalls of cleaning.

It looks like that coin got the gunk on parts of it and then the rest continued to tone. If you soak it in acetone and no more of the gunk or dirt comes off, I'd just let it be and it will eventually retone over a couple of years.

Luster can not be restored on a coin. Once it is removed it is gone. If the luster is covered you can use distilled water or acetone to remove the gunk. Fingernail polish is usually not recommended because it has other stuff in it.

Fingernail polish remover in many instances contains all kinds of Stuff. Women need or want it to smell nice so manufacturers add STUFF to make it smell nice. IF the one you used is like this, that haze may well be from the STUFF in the remover. It would not be worth your cost to go to a hardward type store and purchase pure Acetone just for that one coin. However, check the bottle of the one you used to see if it is labled as pure Acetone. If not, that haze may be from the Stuff in the remover. Not sure if you have any Distilled water at home, but you could try soaking that coin in that. If not, not expensive so next time at a standard grocery store, look for distilled water. Usually about one dollar a gallon.
As most have already said though, this coin is not a really valuable one so spending excessive time and money is good for experimenting but not much for a final result, money wise. As noted it is not a good idea to clean coins but from the first photo, looked like not much of a choice.

I did a reply, which was quite long winded, but it didnt send, so heres a shortened version:

Heres an extreme version of a coin thats had an area protected that hasnt worn along with the coin. This is a coin, both pictures are the same coin:




I wont mention how this happened, I guess people could guess, but its one coin (not two stuck together) and its from a forum member. Its one of the only American coins I have floating about.

"I would have to say if you did not even know what you had, there was a problem before cleaning it. I would not say you damaged it, rather the person who encapsulated it the first time did. It is a similar situation to cleaning ancient coins, it simply had to be done, and the fingernail polish remover's acetone is one choice I might have tried. But, considering where you found it, you had no great loss of investment."

What I didn't say in my original post was that my investment was miniscule.

The box also included, among other stuff, a couple of Case pocket knives, some old jewelery, a couple pieces of sterling silver, and a 1950's era Zippo lighter in new condition. I paid 5 bucks for the box, so the coin was just gravy anyhow. With my new intense interest in coin collecting, it was the most special.

Welcome to CC!

1) NEVER use nail polish remover on a coin. It can and usually does contain more than just acetone (usually ethyl acetate) and those can damage metals.
2) Buy yourself some pure acetone, hardware stores usually carry it.

You didn't "ruin" the coin. If you can't even tell what it is, it must be cleaned, otherwise it's a useless chunk of metal. However, you could have done a better job at removing the foreign substance. Conservation techniques are best learned by experience, consider this your first lesson.

In general, you want to soak using what I have coined the "polarity ladder". For example, soak in order of decreasing solvent polarity (about 30 minutes each to start):

1) distilled water
2) acetone
3) xylene

I do a good bit of penny brick searching - this is simply a required method with many coins. It works surprisingly well. I use as hot of running water as I can stand and remove gunk with my fingers and sometimes a bit of liquid detergent soap. With these kinds of coins there are two choices - junk pile or a quick sink cleaning. Obviously, I prefer to see what I have before I toss it in the return to bank pile.