The ornamental design for a three-way, mitered, drywall corner-trimming device, as shown and described.
FIG. 1 is an exterior, perspective view of a three-way, mitered, drywall
corner-trimming device, showing our new design;
FIG. 2 is an exterior, elevational view thereof, as seen along one of three
mutually orthogonal axes, the exterior, elevational views thereof being
identical but rotated, as seen along the other said axes; and,
FIG. 3 is an interior, elevational view thereof, as seen along one of three
mutually orthogonal axes, the interior, elevational views thereof being
identical but rotated, as seen along the other said axes.
Broken-line showings of tabs extending from the device are illustrative
only and form no part of the claimed design.