Re: laser welder...
I am familiar with laser welded blanks for sheet metal stampings. Quite cool, er, hot, er, you know what I mean. You're probably driving a car that has one in it.
Horn repair is so marginally profitable that I don't think the overhead could be justified. It would take a lot of horn fixes to recoup 30 grand, and soldering can be undone whereas laser welding would be more permanent, thus it's application somewhat limited.
Cannonball probably uses similar technology for their etching process.