So I spent several hours of researching and tinkering with versions of LED flashers in an effort to come up with a suitable home brew LED tail strobe. I believe I found the circuit that will do exactly what I was hoping for.
Using a 555 IC timer chip set up in Astable mode to drive two transistors (PNP and NPN to alternate the on state) I will be able to alternatly flash as many LEDs as I would like. You can watch the tutorial here if you are interested: https://www.youtube.com/watch?v=mBA9uPeEzw4 The earlier videos from the same person "Skinny R&D" go into a lot of detail on how the 555 chip works and how to vary the flash timing.
Now with more parts on order, I will update with additional info soon.
Well, after the parts came in I worked up a test circut on a solderless breadboard. with the output of the 555 chip I was able to drive PNP and NPN transistors to alternatly flash two sets of three LEDs. Once I worked out a few details, ( and fried a few chips ... oops) I built up the final version on a 1/4 size solderable breadboard. All works very well. I used a variable resistor to enable adjustable frequency. It goes from one blink every 10 seconds or so, to strobe like speed.
I machined holders for the light assemblies out of 1 inch aluminum bar stock. I will mount one on each side of the fiberglass fin cap. Next update will be the installed lights