The "American," or "Model 60," is chambered for .32 caliber is a 6-shot double action solid frame revolver made by Harrington & Richardson Arms Co. of Worcester, Mass.
Measuring backside of right panel (vertical not diagonal):
2 11/32" long
1 3/16" wide across center of screw hole
1 3/32" wide - 1/8" up from butt