This Spanish colonial 1/2 reale has undergone some form of double striking, I looked in the the mint error book but can't decide what to call it. Opinions welcome. The reverse design and legend have been struck onto the obverse but flipped over. This is clearly evident on the top and right hand side of the obverse (QUE and VNUM), but with a hand lens I can make out most of the rest, including the central design elements. Here is the reverse flipped over and legend outlined for more direct comparison: My guess as to what happened. Keep in mind these were produced with a screw press operated by hand: 1) Coin remains in press after striking, but flips over (such that the reverse side is facing toward the obverse die). 2) Planchet set on top of coin and the screw press applied by accident and only enough to leave a light indention of the reverse legend and design on the blank planchet. 3) Mistake realized, coin and planchet removed, planchet re-inserted with the slightly imprinted side facing toward the obverse die 4) Planchet struck with normal force, but not enough to obliterate imprinted error. The NE-SW cut across the rim on the left obverse I assume is post-mint damage.
Can't say that I disagree with your comments, it would be a capped die error. Never seen one for one of these.
Actually, it may even have been hit intentionally, until they "felt" there's the other coin in there, then released the press. Either way, though, that's one hot-looking half-bit.
