Original WW2 Memorabilia War Effort Women GMC Factory Lg Color Photo Slides 9x11

Description

Original WW2 Memorabilia Working War Women GMC Factory Large Photo Color Slides.
Very unusual items.
My father worked in the Cadillac division of General Motors Detroit from 1938 to 1968.
There are three extremely nice clear color ‘slides’ measuring approximately 9x11 inches protected between sheets of what I first thought was glass but now I see it is an early type of plastic. The back piece is frosted so when you hold it up to a window you get a beautiful sharp image.
They are sandwiched and held together with a black paper type tape which has held up very well. You can see the tape on the chart images, and I don’t know what material the charts are as they are both encased.
The 4th color slide - showing a metal cylinder(?) heated to glowing orange, is loose and not between plastic although the back frosted piece is included.
I have cropped the 4 main images for my own protection so please be aware you will receive more area and details in each.
The final two pieces appear to be a signal current chart and an electric schematic.
I have no idea what they refer to but were included with this interesting one of a kind set.
My father was also an amateur photographer with a basement darkroom and it’s possible he took these photos himself and assembled them for viewing.