1944-S US - Philippine Possible Error Coin

@Piersol, first welcome to CCF. Second, in addition to a pic of the other side of this piece, can you please also add a pic of the edge? As it is curved, it will be hard to get too much in focus, but that is ok. Thx.

Here is picture side view.

It cannot be a "mint error". While genuine double-headed and double-tailed coins are known, they are extremely scarce and not technically "errors" - they were deliberately made by people working off-production using a press specifically set up to make double-tailed coins. The obverse and reverse dies used to make coins have differently-shaped attachments for installing into a press; putting a "tails" die into the "heads" position of a press would be like putting a square peg in a round hole. It just doesn't fit.

Rather, your coin is most likely a "trick coin", made by taking two perfectly normal coins. One coin is ground down on one side so that it's wafer-thin. The second coin is hollowed out on a lathe to form a shallow "bowl" or "dish", into which the thinned-down second coin is pushed. The "seam" between the two half-coins is thus inside the rim on one side of the coin - probably the side shown in pics 1, 2 and 4 above.

to the Community!