Dimensions / Sizes and more information about the Colt Police Positive Wide;
Measuring right panel (vertical not diagonal)
3 1/8” long
1 9/32” wide across center of screw hole
1 13/16” wide @ butt
Some of the later productions of the Police Positive used a redesigned grip frame with a wider butt.
Grips #3555G ($41.50), Screw Kit #7196 ($16.00)