Sorry, old thread, I'm just getting used to checking dates, and was struck by the coin and responded.
Here's my rarest, 1787 8 reales from the Santiago mint, Captaincy General of Chile, Spanish Empire. Recorded mintage of 183,209 (Elizondo).
Beautiful coin, jgenn! Santiago mint 1,2, 4 and 8 reales for Carlos III are quite scarce. More so the 4 and 8 reales, and specially one as nice as yours. I believe your example is ex Millenia collection? I got mine ca. 1990, and is ex Randolph Zander Collection:
Thank you, Eduard. Mine was in an earlier Goldberg auction in 2007. Fortunately, I bought mine more recently after the price bubble.