Missing pictures restored in the attached pdf (with reworked text to go with the pdf, page by page...). Click on the thumbnail at the bottom and the pdf should open or be downloaded or something....
Page 1 of the pdf shows the external wiring. Switch inputs J1 and J3, when grounded, each turn on a power MOSFET, providing current to the Taxi and Landing lights, respectively. Just one or both lights can be on at the same time. However, grounding the wig-wag input, J2, always causes the lights to flash alternately regardless of the state of J1 and J3.
I lost the drawing of the 4 x 2.3" board I originally posted. Pages 2 and 3 show the top of and bottom of an unpopulated solder-masked and silk-screened board. Page 4 is a (mostly populated) "bare bones" prototype (no mask or silk screen), showing the input and output 0.25" Faston tabs (J1-J8) along the left and right sides and the blue trimpot R1 which sets wig-wag timing. At mid-range, wig alternates with wag over a ~2 second period (i.e, 1 second on-time, each side). I ran out of Faston sockets for the ATC fuses when I stuffed the pretty green board that's in the plane: so I de-soldered the FS2 and FS4 sockets from the proto board.
I mounted the board on the subpanel with aluminum standoffs at the the four large dia vias in the corners of the board. The vias contact the ground planes on both sides of the board, so those ground planes are connected to the airframe through the standoffs. I bent up an Alclad cover to go over the top of the board (also grounded), in case something tried to fall on and short the topside components one day. However, the cover doesn't completely enclose the board; the ends are basically left wide open to give access to the Faston tabs.
Whether not any of the lights are steady on or completely off, the wig-wag oscillator runs when power is applied to the board, and the sharp edges of the CMOS square waveforms could cause EMI. I generally flip on the wig-wag before engine start and turn it off after shutdown. In flight so far, there's been no hint of noise in the radio or intercom as the wig changes to wag and back again. If I listen very carefully, there seems to be something barely audible coming through after the engine stops until I get the Hobbs and Tach time from the Dynon EMS and open the master contactor.
As always, YMMV.
The circuit schematic is shown in the pdf, page 5. Maybe a little easier to read than the 800 pxl wide picture in the original thread.