A few things for future searchers:

The pulsing lights was traced to a faulty voltage regulator. There was spotty contact between the regulator pickups and alternator brushes. $35 (NAPA) for the regulator and all is well in that department. Apparently, Benz sells the bushings as a singular item so you could probably do this without replacing the entire regulator for just a few bills.

As for the headlight switch......Caig Deox-it did the trick. I keep this stuff around for potentiometers that constantly go south on the old tube audio gear I play with. (partsexpress.com) has it for about five dollars. Spray it in, work the switch through its motion a couple times, then let it dry for a good hour. Disconnect the battery before you spray liquid into switch.

I'm not sure about the friendly wiper. Since repairing the other stuff it works as it should.

I'll report back with any further developments.

Sam