I think you have a nice genuine 8 reales there.
I do not believe the coin is seriously damaged in any way and I certainly see no cause at this point to even suspect it has been mounted.
The "chipping" along the upper rim Cap side and the lower rim eagle side is actually caused by the way the planchet was made. It is very common on Zacatecas coins of this period. The blank was likely made on a worn punch so that it has fins of metal attached to the blank. These were not removed in the adjustment step (likely so the planchet would not have to be rejected) and the edging process rolled the fins over the face. The final strike drove the fins into the face of the coin.
At times parts of these fins will loosen and fall away but it is clearly not really serious damage when the nature of the cause is taken into account.
It will never be a high grade investor coin. Be thankful for that. As soon as coins in this grade become high priced the average guy is priced out of the market. That is bad for the hobby.
The price of $25 is great in my opinion. Much better than spending $100s on a counterfeit in a
TPG holder.
I congratulate you.
For me the scratches give the coin character and show it was really used. To me they do not detract from the beauty of the coin at all. As a lifelong collector of counterfeit coins, I have never cared for pristine coins straight from the mint that were never used. They are antiseptic and cold looking - honest wear gives a coin life and warmth.
Of course my opinion is based on my view that ultimately the high grade high value collector's bubble will burst. The people who paid thousands of dollars for common coins in high grades will lose far more than you are risking.
This statement of course presumes you are not someone trying to make a big profit off every coin you buy. I am a collector not a seller. These coins are my babies and I do not like to part with them. They are history you can touch.
The clamor over MS this or that is (in my own opinion) totally stupid and has been generated by the big money dealers and non-collecting investors who have no real interest in the coins beyond the profit they can make. I know many guys like this - they buy coins to throw them into a safe deposit box. They never study them, never study how they were made or how the subtle clues on the surface tell a story. Those people may have a lot of money but they are missing the pleasure of collecting - the joy of learning.