Brad, thanks heaps for trying. I really appreciate it.
I'm going to have serious trouble finding a switch like I want.
Unfortunately, most bikes and scooters have the light on/off switch incororated into the ignition switch, with only a two-position switch for high/low.
Because of the dual headlight setup, I can't use an ignition or other single switch for on/off, or both lights will come on together. Otherwise I could use one on/off switch with two hi/lo switches.
I did a search today and still couldn't find anything suitable.
I'll have to think about another method of switching to control 1 to 4 filaments easily.
I'll probably add some electronics and make a small box with waterproof pushbuttons and LED indicators. (Much more work, but then I'll have exactly what I want.)
Thanks again for your efforts, Brad. I owe you one.