My Dad left me an April 1952 NathaN AirChime MS-1 with the bell flare cut down. Looks like it was cut a long time ago, most likely for clearance purposes. These types of horns were used on many switching locomotives back in the day so there’s no real way to figure out what exactly it was used on. I don’t know much about it and was helped with the above information. I don’t know if it works either just thought I would see if there is any interest and what it may be worth. I have pictures. Thanks DJ