Well, I am happy to report that I followed RF's recommendations, cleaned the gun, returned to the range and shot 250rds of 115g Sellier & Bellot without a single issue! Thanks, again, RF!
Earlier this week, while dry firing with snap caps, I realized the gun moved around in my hand quite a bit. It occurred to me that I normally wear a medium to large in motorcycle gloves, so I decided to swap the small backstrap for the medium and I think that helped. The gun felt like a better fit and the movement I noticed seemed to subside. My shooting at the range seems to reflect improvement as well. As RF suggested, I was fresh and less fatigued and just holding and aiming the gun felt more natural.
My first shot was just slightly to the left of the 2" bullseye. I did have a tendency to shoot low and to the left which seemed to happen anytime I anticipated the recoil and I suspect I tightened up or flinched. When relaxed and deliberate with my finger where the shot surprised me, I could hit center or very close to it with successive shots.
This gun is clearly accurate and a really fun gun to shoot - such a good choice for me in returning to shooting. I shot at a couple of body/head shaped targets and did pretty well at 7 and 10 yards hitting just left center mass on the body and consistently hitting the smaller boxed head area.
Other observations: 1) shooting is an expensive hobby! I did the math today and spent $85 (5 boxes of ammo @ $13 each, $15 for lane fee, $5 for targets). I do not recall this sport being so expensive! Granted, it has been over 20 yrs for me. 2) .45 cal 1911s fired in the adjacent lane are loud and concussive, even with good ear protection! 3) by contrast, I could barely hear the .22 target pistol on one side of me, but that older fellow placed his shots within a 2" radius clip after clip, dead center!