Here is the bottom view as requested. Top bore is 2-3/8" to match diameter of lens. Bottom bore is 2-1/4" to help form a thin 1/16" shoulder for glueing lens in place. A little squeeze out lets me know that the glue has seated against the edge of the lens. I use Titebond2 for this application because the edge of the lens is sanded.
3/8" recess cut to prevent information from getting rubbed off. www.perfectwoodworks.com
I like this idea a lot and would like to make one for my mother but I cannot find a supplier where I can buy the lens. Is it easier to just buy a magnifying glass and remove the handle it comes in?