I'm probably stating the obvious here, looking at the lack of bash plate and the tires, but I gather your riding doesn't include many worries of crap coming off the front tire filling the horn? Looks like a purpose-built mud catcher.
Not slagging your work and I like the idea, in fact I keep mumbling about replacing my stock horn, but I'd wonder how long that horn would survive dual sport riding
I assume you can orient the opening in any direction you want, however?
More closeup pics?