Many many years ago I found an original Mark IV under dash unit in a 60 Chrysler in a junk yard and bought it. I did a cosmetic restoration and painted the case interior color. It has a beautiful chromed metal face and vents and a little thermometer in the center of it.
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View attachment 171612333457 Int[/url] by
https://www.flickr.com/photos/153889607@N08/]M Patterson[/url], on Flickr
It found a home in my 57 Plymouth and even converted to 134a it will freeze you out (at least in the front seats LOL).