Leslie Tyfon horns.
I suspect one of the horn-aficionado Web sites can give you bell dimensions and tunings.
Try the historical society, that's where I got information for the diesel horn for one of my roads locos.
Good luck,
Richard
I recently gon a really fine Rapido RDC decorated for the NYC M457. Anyone know what type of horn NYC put on them in the later years. I have a couple of Leslie A200's but I don't have any really clear shots. They appear to have 2 chimes, with both facing forward.
Thanks
Paul
Dayton and Mad River RR