Anyone done Under Dash A/C ?
The appearance of the add-on A/C units back in the 60s varied more because of the manufacturer than what the application was. Also, the ones from the early 60s looked different than the late 60s early 70s units did. As time went by they were restyled to try to make them look more modern.
The big 3 all offered them, starting somewhere in the late 50s and continued into the 70s. I'm not sure when they were discontinued, but I do know that Chrysler offered them well into the 70s for B-vans.