Yep, round butt Model 12 with work by Karl Sokol. The grip is the custom Herretts’ Detective model, made to measure to your hand and the gun. In addition to hand tracing, I also traced the butt of the Model 12 - figured more info is better on a custom job.
The Herretts hand trace was pretty easy. Probably even easier if you had a partner to hold the pencil. The vertical dimension was amazing, tailor fit. The fit to the frame was clearly hand relieved - not messy, but you know it was not all CNC. The fit is tight, as there is an audible 80ish decibel SNAP sound when the stocks pivot on and down from shoulders.
I have stubby fingers and did find the left panel a bit too wide, as it made my arthritic right thumb splay out under recoil. I do not enjoy the Airweight recoil anyways, so it was a might uncomfortable. Not a criticism of the Herretts profile per se, as they had a slight thumb rest contoured in but low profile enough to avoid speed loaders. My thumb length just landed on the highest/thickest dimension.
Pre-adjustment profile
I chose the rubbed oil finish, no checkering in part if I wanted to do some adjusting. A few grits of sand paper and a trip to get some Tung oil, I have the left panel thinned out a bit. Effectively I removed nearly all 1/8” thumb rest contour. Viewed from behind, the panels are not symmetrical, being thicker on the right panel, but still is shootable from either hand. Giving the Tung oil some time to dry before I shoot it, but looks pretty close to Herretts’ finish.
Needs a few hundred more rounds to fully recommend, but looks good, feels good so far.