The rest of the story...
I contacted the original ambulance squad that purchased my 1969 Miller Meteor new, and asked if they had any pictures of the car. The only pictures that they could find of the car were on the day that it was being taken out of service. I noticed in one picture the siren was mounted on the roof, and in the next picture, the siren was missing. On the outside chance that it might still be in there building, I contacted them again and asked about the siren, telling them what I had noticed in the pictures. I was told that they would look for the siren, if they knew what they were looking for. I sent them a picture of what a Q looks like, and got a call back the next day. They had located the siren and were going to send it to me if I would pay the shipping. I paid the shipping and also made a generous donation to the squad. It arrived yesterday..