Thanks, @aramkolt! Meanwhile, I have learned a few things and taken action:
- It's called a "splash cap" and many slide switches allow a variety of these when specifying the switch (Not easily found for this switch though)
- It's made of 6/6 Nylon aka Nylon 6 aka Polyamide 6 aka PA 6 (plastic)
- I'm waiting for the glue to dry on a repair job:
* Clean with Isopropyl Alcohol
- Use appropriate glue. I'm using Loctite Extreme Gel that I had on hand
(For this glue: clean, dampen slightly, use a pin to put on one side of the crack, wait 5 minutes, clamp shut, wait at least 2 hours or 24 for full strength.)
Here's hoping it works!
And yes, I am guessing that "auto" position is likely all I ever need.