1976 Nathan Airchime P5A
This is my 1976 old cast P5A. I built the horn out of parts obtained from various sources. The rare 3 piece low profile P manifold was from a P01235 that was on eBay in early 2020. I bought the manifold, left the app and the P0 bell showed up about five minutes later- sold for 200 dollars!
The three piece manifold is an original one, not a one piece that has been chopped up. The easiest way to tell them apart is that the "wings" on the two outer sections don't have metal webbing between them and the main part of the manifold. There are also separate part numbers for each of the three pieces.
Ah well, enough of me rambling- these horns were used on Amtrak P30CH's, Turbo Trains, and the first order of F40PH's. Nowadays they can be found on some Metra locomotives in the Chicago, Ill. area.