Bad Hand,
I practiced one-handed rifle shooting a few months ago, just in case I had to do it (I don't, at least not yet). I found I could do it with a Rossi 92 carbine that is slightly muzzle heavy. I did tuck the butt under my shoulder and worked the lever sharply, but not as fast as I used to. It was really slow because of the extra effort of putting the butt under my shoulder after each shot, then back to shoulder, reacquire target. IF I ever have to go the one-handed route, I would make a buttplate with the long extension to the toe of the buttplate, often seen on schuetzen target rifles. Hopefully, that would allow me to keep the rifle on shoulder while levering. Maybe even a full schuetzen buttplate would be better.
I too have watched the same one-handed shooters as Doc Schapiro. They are were not the slowest shooters at monthly matches.
Best Wishes for finding a good solution,
Lars