Sat Jun 21, 2014 5:15 am
If I had to guess, in 1942, model 2s, 3s, and 5s would be fairly accurate, as these were the most common fire sirens of the time frame.
Still close enough to a Fed Sig 550AT to drive out on test day: First Friday in May - 7PM!
As of April 15 2010, a certified NWS Skywarn Spotter.