3mm LEDs arrived today, 10x red, 50x white. We're gonna need a bigger bag of white LEDs...
After doing some drilling today on the original reflector to actually determine how many 3mm LEDs I could comfortably embed into it I discovered I can get 60. Yes, 60, 6 rows of 10 holes drilled in the reflector won't adversely affect the structural strength of it and it will still partially work as a reflector:
You can see the test row of 5 holes on the right, then test row of 6 on the left and a partial grid in the center. It's going to be well over 3x the brightness of my present 17x 5mm LED setup which enables me to see along unlit paths/roads quite easily, I love cycling at night so things are going to be even more fun!