Alan,
"Can anyone enlighten me? Does anyone sell original horns? I don't see them in my Chevy Duty catalog."
The '54 (and I think '53) trucks came with a low-note horn, and a high-note optional horn was available. The car had the same horns but different mounting brackets. The horns have "mirror image bodies". In 1954, both horns mounted on the radiator frames but in '53 the regular horn mounted on the radiator frame and the high-note horn mounted on the intake manifold (odd looking).
Chev's of the 40's used to have the standard horn but I have never seen any vendor selling the accessory horn. They are both available on eBay every so often (search on combinations of " '53, 1953, '54, 1954, Chev* horn* " ).
The sound you are describing seems to be mellower (lower) than the original dual horns but, so what?
Good luck,
Tim
