Cool story bro...
Actually, that is a cool story and if ever I get one of my dream 80s cars, I'd love to put a multi-tone tune-playing horn on it, probably wired to a separate circuit, just for the horror factor... and to go with the CB radio, of course.
However, I was led to believe (by Mr EV here at work, again, who will NOT shut up about the darn things) that it was the regulation prohibiting use of your horn between 11.30 pm and 7.00 am that also applied to any other noisemakers on a vehicle and was thus why you couldn't even get one factory-fitted as standard.