For those of you (not too many I'd suppose!) who were at one of the PUBs years ago in Blacklick, I talked about my own "restoration" of Bosch horns.
I got a pair from a fellow member here many years ago, functionally they were trashed, but the cases were fine.
I disassembled, and had the cases powder coated and bought a rebuild kit from Stoddard. It was basically tags, screws and not much else.
I cut new paper gaskets out of heavy "oil paper".
I bought a set of SEALED Bosch horns, smaller, and placed them inside the old cases, running heavy duty wire to the terminals.
So they look perfect, from the outside, and being sealed, will last.
Note, because Stoddard deals in old Porsche parts, at the time I did this (2007) the only tags I could find were theirs; they were for 6V horns. Of course my horns are 12V. I have since replaced the tags with 12V proper tags.
Y'all can laugh now, but these things were so darn pretty I could NOT stand to actually mount them on the car! So they are in a box, the Crown Jewels of my Pagoda parts!
What's actually on my car now? I don't know. The restorer got them 20+ years ago. Not original, not hardly--but LOUD.