I had an eerie feeling that you were going to say that. Those ones are very hard to get a hold of, and plus I'm guessing people don't really sell them. but all is not lost, because there HAS to be someone who custom makes them. But you should probably just run some extensive tests on this.
To answer your first question, just drill some holes in a drillable place and with machine screws secure it to the horn (preferably the "t" shaped horn).