c.sam posted:"sounding like the original" is a dismal prospect! As a boy I was sorely disappointed with the Gilbert 'Air Chime Whistle' and the "Air Chime Horn'. The 'Diesel Roar' was decent but the horns & whistles sounded like nothing I had heard by real RR tracks before....
Aw-gee. Call it nostalgia, but I kinda like the Gilbert "Nathan air chime" whistles. 
Depends on the sample. Some were better than others (circa mid-50's). Used as a diesel horn in the PAs, it is really not any worse than Lionel's bicycle horns. Of course, the synchronized smoke and choo-choo conquered all.
Bob
