HMMMM.... 1881 Republica Mexicana - GoS.902.7 , 10 Centavos - that isn't Silver...????

found this in the horde I am digging through currently.. it isn't pretty.. has a bend and cut marks in it above the date.. but it is a Gold / Brass-ish Colored..
I tested it with JSP acid & a scratch Stone.. got a negative result for silver instantly. .. even tested a 2nd scratch with 18k acid to see if the scratch turned blue.. negative on that as well.. did a third scratch test with 10k gold acid.. it held for about 2-3 minutes.. 4th scratch with 14k was a quick negative..
pictures show it in comparison to well known composition coins including a 1903 Barber Dime.. which is 90% silver..
the 1881 Mexico 10 centavos is also supposed to be 90.3% silver..

am I missing something here.. ??

here is the catalog ID for the 10 Centavos from 1881.. there isn't any reference to metal composition variations..
https://en.numista.com/catalogue/pieces15262.html

It is a nice replica/forgery/fake/copy....
(I think)

just seems weird to be a fake forgery... it would be obvious it isn't silver.. completely wrong color..
could it possibly be some sort of test coin to see how the " coin making machine" is working properly... like some sort of prototype or something..?
( LOLOL.. yeah I said Coin Making Machine.. )

Verweis : "PlanetEarthToys"​just seems weird to be a fake forgery... it would be obvious it isn't silver.. completely wrong color..

​Perhaps it was once silver-plated, but over time the plating wore off; that's my guess.

As for whether it could be a trial strike or pattern coin, I seriously doubt it; much more likely just a contemporary counterfeit.

I think i had the same situation with 1873 one, didn't tested it but thought about that few days ago when I saw it