"I have read that these peep sights were only used to sharpen the focus of the barrel sights not as we use aperture sights today. Thoughts?"

I believe this to be true. They are diopters for sharpening the focus on iron sights.

You can buy diopter devices that stick on your glasses for target/competition shooting. Available at Brownells https://www.brownells.com/shooting-acces...s-prod8767.aspx

Vlad