Richard, hope you start feeling better.
Rick, I don't think you are thinking big enough for the replacemnt horn. I think this is what you need. For vessels over 75m in length.
Model D-2 Air Horn | Kahlenberg
My Cobra has a little beep beep horn. It is near useless when the car is running.
I tell ya Glen, Avons. True vintage racing rain tire. You probably only get 12-15k miles on them though.