My rapid prototyping has already taken care of a rear sling swivel stub. It was fairly simple to remove the grip cap medallion from the stock. I carefully ran a scalpel around the edge, and noted that the blade went in deeper, and hit something solid, part of the way, and went in less, and hit something mushy, in other areas.
Bless their cheap little hearts, but the Ruger beancounters decreed only a bit of glue be used. I cut through the mushy areas as best as I could with the scalpel. The a quick pry with a thin-blade screwdriver, and it popped off without fuss. Ten minutes to study the problem, ten minutes to find the tools, and two minutes of work.
I found a QD swivel stud with a 10-24 thread, and determined that the top of the "R" was as close to absolute center as I was going to get. A #10 drill, washer and lock washer, and nut, and everything was snugged up to the grip cap.
With a more generous application of glue this time, here's the final results. A flat plastic plate inside the pistol grip opening wouldn't stick out as much, but this gets the job done. I didn't want to tackle the toe of the stock, even though it appears to be solid plastic for the last half-inch of the stock. I wood screw stud might work, but the grip cap medallion was quicker and slicker.
And, I decided to give Little Bro a sporting chance, and temporarily installed the Trijicon ACOG for accuracy testing, even though the scope probably is worth at least three times more than the entire rifle.
So now I can test with my "calibrated" ammo to see what, if anything, Little Bro likes best, before I switch back to iron sights.