Subject: Mobile Telephones (Late-1940's "Educational" Film)
12/10/2020 @ 20:50:38: Ddey65: Mobile Telephones (Late-1940's "Educational" Film)
I found this old video of a late-1940's ephemeral film produced by AT&T about old-fashioned mobile telephones called (what else?) "Mobile Telephones."

Pre-1950 cars, trucks and buses are all over this one. Maybe somebody could add this video. Or maybe I can, once I find an exact year and other details.