I will reply in order to the comments. doges
You say that the coin has a rim. The problem here is the raised rim seen beyond the dentils on the face of the coin. This is impossible on a collarless screw press.
The dentils at the edge of the coin must run off the actual edge so that any filing to steal silver will be noticed.
The coin is a Numismatic Forgery worth melt only. Most of the examples I have seen of this exact type contain ZERO silver. The coin is basically worthless. keepcalmandcoinon
I've seen that "rim" on other examples and have been told its excess metal being pushed up out of the collar.
The person who told you that is not familiar with the system used in Mexico to strike coins. At this period in time there was no collar at all on the press.
The first development (during the second Republic) was a centering collar which positioned the planchet but did nothing more than that.
The true closed (close) collar appeared very late in the Cap and Ray series and was associated with steam powered presses or other non-manual types.
So if you have seen other Portrait 8 Reales with a raised rim, you most likely have Numismatic Forgeries - not even silver restrikes made for the China Trade. They are all worth melt value no more, even to a collector like myself.jgenn
You say that Portrait 8 Reales were NEVER struck in a collar - that is correct. Slightly Lithuanian Zac
You ask about a specific coin an 1806 Mo TH 8R with a drill hole near top center. That coin is in my opinion genuine (or at least silver). Without seeing the actual edge I can not rule out a silver restrike made outside of Mexico, but since they are still being treated by 99% of people as if they were genuine you would not loose too much value.
In this case the drill hole seems to display some suspension wear at the top of the drill hole but not a great deal. So the coin was suspended but not perfectly upright. When a drill hole occurs on the sides of the coin or the bottom - the reason for suspension might have been that it was a counterfeit and it was placed on a bank teller's loop for future reference.
This is a common date and the price is horrific for the coin pictured. $ 30 or $35 perhaps as a hole filler. Poor investment unless you plan to add a stamp and create a fake rarity. (Which I say only in jest.) Gincoin43
The edge has not been filed off and replaced. The clues for that kind of a coin start with little or no dentils remaining.
This coin is a Chinese Numismatic Forgery made after 2010. In my records I have a notation of 7 different Chinese sellers using the identical pictures to sell copies of this same coin. It is a non-magnetic white copper struck usually underweight but made on thicker than normal planchets so the weight is higher than 20 grams. The edge design uses a standard colonial edge of alternating circles and rectangles but the edge never looks "correct" if you have viewed any great number of Mexico City mint 8Rs.
While this coin used to be posted by Chinese sellers, it now is posted on eBay by US sellers or Chinese with US addresses.
My book on Counterfeit Portrait 8Rs is available from Amazon http://ccfgo.com/TheUnrealReales
or from me directly if you want it signed.