The back is very shiny and magnetic. The front is duller and a magnet won't stick to it.It does not have any corrosion so I'm thinking perhaps it's all steel, but of both the ferrous and nonferrous types--thus only one side is magnetic. Or to put it in cosmetic rather than technical terms--the metal has a mirror-like finish on the back--the front is a brushed aluminum look. The piece has wear consistent with age--in fact the patina authenticates that the retro cool isn't just effect but truly vintage.
It's a solid piece weighing close to 3-lbs. The significance of the metal and glass construction lead me to believe this is an industrial piece, and would have been used in some type of commercial building theater, office, store, school, airport, etc. The cord has a in-line switch but the switch is close to the box.
In replacing the cord I would suggest the in-line switch be midway so that it could be easily turned off and on if it were mounted high above a door. There is no maker's mark that I can find but it does look exactly like an item I used for reference that was made by Day-Brite.
However there are many markings in the interior--stickers include a Underwriter Laboratories "Electrical Light" certification, a Union Made sticker, and maker stickers for the bulbs, both Sylvania. I found these when I opened up the back--easy as it's held in place by four screws--I did use some compressed air to blow out the dust but I did not attempt to make any modifications or replace anything. Materials: metal (steel maybe some aluminum/glass/acrylic).The item "Vintage Day-Brite Lighted Metal Acrylic Glass EXIT Sign Green Corded 1960s" is in sale since Monday, October 7, 2019. This item is in the category "Business & Industrial\Facility Maintenance & Safety\Safety Signs & Traffic Control\Exit Signs". The seller is "madamolli" and is located in Cleveland, Ohio. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, South africa, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Israel, Mexico, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Chile, Colombia, Costa rica, Dominican republic, Panama, Trinidad and tobago, Guatemala, El salvador, Honduras, Jamaica, Sri lanka, Uruguay.