Obverse 15 is identified by date placement at LH with a misplaced digit
located in the denticles below the rigth side of the final 8.
Reverse Q is yet to be observed with any die markers.
Comments: The
Obverse 15 misplaced digit may well be a 4 digit from an initial digit
punch impression that was rotated counter clockwise with respect to the
final date placement.
Plate coin:
Images courtesy of Ed Nathanson, XF40 details