I remember making that holster. Probably about 2011 or so, if my old rememberer still functions (my fergitter is working a lot better these days).

The "dog ear" is actually a hammer shield, intended to protect the user's arm and clothing from contact with sharp edges of the hammer and rear sight. Based on the designs popularized by Hank Sloan, and frequently referred to as a "Hank Sloan-style" holster. Popular with plain-clothes cops back in the 1960's and 1970's. I first saw this style holster while attending a brief training program at the FBI Academy at Quantico, VA in about 1971 or 1972. I found it to be quite useful for keeping the linings of my suit jackets from being torn to shreds by the hammer and rear sight, and I made quite a few of that style until the latter 1980's when semi-auto pistols started displacing revolvers in cops' holsters.

Your Herrett's "Jordan Trooper" grips are another blast from the past! Very nice!

My avatar photo shows a very similar holster made for my old 6" Model 19 with a very nice hand carved floral pattern. One of my personal favorites.