There is a 1950s film titled "The Day Called 'X'" which has footage of Chrysler sirens rotating. I'm not sure if the sound is accurate or not. Anyway, it was made to show how an evacuation should work if the city of Portland, Oregon was under nuclear attack.
I love how whenever they have someone talking about the H-bomb that's on the way, the screen shows "THIS IS NOT AN ATTACK," since apparently it was televised. It's a good look at how serious this was at the time.