I like that description Kook " It is NOS but it has been repainted ". Funny, I dont see the original NOS box anywhere. My guess is its a used horn that has been painted & the hardware has been replaced with new shiny stuff.
Check out this one.....
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2428084501&category=34202