Howdy ET44C4,
Great sounding mod! I'm sure it took ALOT of effort to make.
Just wanted to let you know that horns that are operated via a button from most modern 'desk type' locomotives are not capable of being 'quilled'. This is because there is an electric circuit that connects the button to the horn verses a valve (like in the F40, or most early locomotives). You can make really short pushes of the button but there is a delay so doing things like 'shave and a haircut' is tricky, or at least I think so anyway.

Anyway, don't let me discourage you. I hope you release the mod, it would be fun to use anyway. I just mentioned that for your information. Please, I meant to harm.
Take care
P.S. I always thought it was funny RSC did the same thing with their F59, which also had a horn button. Ah well, still a great locomotive.