An update from Federal Signal: they were able to send me a few scattered catalog sheets which people might like to peruse, but no wiring diagrams or maintenance manuals.

Dear All: I recently purchased the above horn on an eBay auction, and as there have been different horns with the same Model Number along with several companies close to Federal Sign & Signal, I've been rather unlucky digging up information on it, other than I believe it to be a military surplus...