2 Heads, one white, one with red, green, blue and amber LEDs, heads and color LEDs individually controllable.
The modified MCPCB with XP-E2 color LEDs, and my driver which is used in both heads. In the white head populated with FET + 7135, in the color head populated with 4 x 7135 for each LED. MCU is Attiny 841. Full ramping UI of course. The reflector bottom had to be grinded a bit to make room for the outer LED wire pad. Reversed MCPCB polarity (batt+ at the outer trace to keep grinding at a minimum).
Cut a solid 6mm brass rod and soldered a spring on one end in order to bring batt+ to the rear head. Used tape to isolate the rod and drilled a hole in the tail PCB.
The threads at the rear end of the battery tube are too short to reach the driver board so I made cut outs (for the PCB screws) to a copper ring and put this ring above the PCB.