Since I got some good advice in this thread, I wanted to let folks know that I have made some improvements.
First thing, I got prescription shooting glasses that allow my head to be positioned properly. My old glasses had small lenses, and I ended up looking over the top of the lens while shooting prone, unless I cranked my neck into an uncomfortable/unnatural position. New glasses solved that problem.
Second thing, I realized my elbows were too splayed out, and I needed to get them closer together .
Third thing, I realized I could not effectively shoot prone if I had just eaten two eggs, 4 pieces of bacon, two pancakes, fried potatoes, a pear, an orange, 3 prunes, and a half a pot of coffee... this should have been obvious, but I have a habit of eating a large breakfast on Saturdays and skipping lunch... but prone shooting is best done with an empty stomach and bladder...
Thanks again to all... my scores have greatly improved.