Fire Alarm car horn

Sorry if this is the wrong section, but I found this on eBay, an Edwards Adaptahorn, with a Nissan car part that doesn’t even look like it will fit the Adaptahorn, and I was wondering if anyone makes kits to connect old horns (preferably Edwards) to other vehicles, (preferably) replacing the factory horn with a Fire alarm sound. I think it would be cool if when you pressed the horn, an EST Integrity horn sounded. I know you might have to keep the Original Horn for Legal reasons, hence why I said preferably replacing. also I find it funny how they spell Nissan as Nissian. Link to eBay item

In theory, any 12v horn could be wired up to the car, but I don’t know of any particular kits for them.