Sea cocks: Bronze or composite?

Uh, Yes, I know. I thought we were talking about thru hull hardware.
I'm guessing somewhere my S/E swamp accent is causing some translation issue with terminology.

I hate Rule stuff, but I don't like Ultras, either.
Imho, it's better to leave any electronic components nowhere near bilges.

Not sure if by "I'm replacing" you mean that you already bought the things.
If not, you might consider this alternative.
You'll never find these switches in chandlers, since they are meant for industrial applications.
But you must hit them with a hammer to make them stop working - no matter how harsh the working environment.

Looks like the original Hatteras level alarm float switch.
Always wondered why they were not use for the pump switch. Maybe no protection from bilge debris?

I wasn't aware that Hatteras ever used them.
I've only seen them on very few boats, and they were all from Italian builders.

Anyhow, yes, the fact that those components weren't specifically designed as bilge switches means that the builder (or anyone interested in retrofitting them) must put a bit of thinking in their location and installation, but their reliability is well worth the effort, imho.

Below is just one example of a possible bilge installation.
The two lower switches are meant to turn on/off the pump at different levels, and the third is an additional alarm, meant to go off if and when the level goes above what the pump can cope with.
But they can be used in any configuration you can think of, since individually they are just extremely simple on/off contacts.

Indeed. In fact, that photo was taken upon inspection of a 14 years old boat, with all the switches original and still as good as new.

I'm not familiar with ABYC requirements, but I doubt that Gavazzi (the producer) bothered to consider them.
Nautical market is meaningless for them, as all their components are meant for industrial applications.
That said, I've seen the above parts also in a vessel built to Lloyd's +100A1 rating, FWIW.

Now, Send pictures of your ship and the hardware replacements. Fill us in on your other projects.
Some of us like to watch...