I posted some stuff about this siren in March. See this thread here.
About the 10th reply down from the top..... http://www.airraidsirens.com/forums/vie ... sc&start=0
The horn is in a different position than it was in March.
Excellent pictures! We really need more pictures of these kind of sirens. They're very rare, you know. Great angle, too. Especially when comparing the horn size to the cars below it.