Need ‘35 horn parts

[Model51]

I have several horns from 1935 commercial and trucks. There must have been two different manufacturers as there are two distinctly different internal configurations. Maybe Ford changed the specifications along the way and one is an early style and the other a later style? I'm inclined to believe it's two different suppliers.

One style is complex and includes a capacitor. The other is much simpler in design. The simpler design is attached with bolts while the more complex design uses threaded holes and screws as the attachment method. Maybe someone with more knowledge can add some identification details.

Also, I've heard that the reproduction horns don't work well.