What Type of Siren is This?

[Danimal]

Hey, I saw this pic on the Schwinn Forum and the Royce Union siren looked interesting. Apparently it already sold, but now I have to know what it is exactely. Looks like a siren that is activated with a brake type lever? Anybody ever see one? Perhaps have one to sell me? It would be perfect for my build off bike.

 

[aka_locojoe]

I think the lever engages a drive wheel on the tire? From what I hear they are hard to come by and pricey if you do.

 

[ODDER]

There are two of those for sale at Bondies antique mall in Wichita.
I believe they want like $120 each but they are new in the box.
Would love to own one but thats a lot of coin considering thats about 5 time what I have in any one of my bikes
and about a fifth of what I have in my car.
Thats right I'm perpetually broke