Great! Thanks to all that responded. Those look fairly close to the Fiamm Fultones available now and also the ones in the current ebay auction. I might get the Fiamms or the ebay ones for now and keep looking for originals. They will be supplied by a small 12 volt compressor and 1.5 gallon or larger tank, both mounted under the bed.
I saw a 1966 tractor in an old magazine or book that had the air horns mounted about 8-10 inches inboard of the drip edge, pretty much over the driver's head. I'll try to find it for placement reference also, but the pic was small and you couldn't tell anything about the horns from it other than the location viewed from behind.
Air horns aren't something Emily needs, but it would be cool to have them!
