Sadly, the best relief wasn't from what I was "taking"; it was from a peripheral nerve block.
https://www.healthlinkbc.ca/health-topics/rt1576
During recovery, I had zero pain in the left shoulder. Biggest pain I had was in my right shoulder that will undergo surgery when the left one heals.
Surgery was Thurs at 7 am. Nerve block was just before. It started to wear off a little bit by that night, and I was warned it would be gone by 3 am Fri morning. So, we starte percocet at midnight to stay ahead of the curve. The nerve block didn't wear completely off until about 5 pm last night (Fri.).
Will give more details tonight.
Thanks for all the support.