The PTT switch on Mary’s Tour Easy became intermittent:

It’s been sitting there for least five years, as witnessed by the sun-yellowed hot melt glue blob, which is pretty good service from a switch intended for indoor use. The 3D printed button never fell off and, in fact, was difficult to remove, so that worked well.
I took it apart and cleaned the contacts, but to no avail, so her bike now sports a new switch with a similar rounded dome:

I clipped the wires a bit beyond the terminals and soldered the new switch in place, so it’s the same cable as before.
Now, to see how long this one lasts …