Got my first project car (1965 289 Coupe) and I'm having trouble identifying this part... never seen it before and even has my grandfather stumped. Wondering if anyone knows what this might be?

 

It's been a long time since I had my 1965 convertible but I don't recall anything like that under the hood. And I did a lot of work to that engine. That label isn't a Ford label either - wrong font and Ford never used the Mustang reared up on its hind legs for a logo.

 

That looks like JC Whitney Special. It isn't a horn, is it?

Definitely not OEM.

 

After a lot of searching I found a small hidden button underneath the dashboard... it appears to be a horn after all!
Thanks for your replies!

 

Does it work?