TRIDON / NOVITA LL525 Electro-Mechanical Flasher - 2 pins - 6v ~$14
TRIDON / NOVITA LL535 Electro-Mechanical Flasher - 3 pins - 6v ~$16
Both should work on positive/negative ground.
Neither will work with LED bulbs, unless you use a load resistor.
Does anyone have a lead on load resistors?
I think I have already bought some - if this works? Would 1 on each side do the job, or, do I need 2 on each side?