Antique Optical Eye Test Machine - Great Mechanism for hidden Art - For Parts or

Description

Antique Optical Eye Test Machine Great Mechanism for hidden Art. Selling For Parts or Restoration 1923
"General Optical - Genothalmic Visual Test Apparatus"
"Pat Applied For"
"General Optical Co. Inc."
"Mount Vernon NY"
Selling For Parts or Restoration 1923
Ideal for Steam punk / Art project
I took this apart about a year ago to see if I could get the mechanism to work. One of the brass parts on the middle shaft keeps slipping and needs to be brazed or otherwise fastened to the shaft. That's where I got stuck. Now I'm selling it for parts.
This machine was designed to flip between 9 moveable cards looking through various lenses.  The cards flip left and right. There is a tenth card that is stationary on the right and rotates  I was imagining getting it to work and replacing the eye charts with paintings or prints for a peep show.
The eye chart  would move forward and backward with  the middle knob. There are various types of lens viewers and colors on 2 layers. I don't know what this machine was designed to test. It has some rust. See pictures
DIMENSIONS: Overall 19 1/4" wide X 15" high X 11 1/2" deep
The Front black panel 17 5/8" wide x 13 3/4"high
The depth of the box is 11", not including the viewer & knobs.