4c080be
seemed to swap the LED pins for the 20130602 and 20140521
variants. 20140521 is fine now, 20130602 untested but per the
schematics at https://deskthority.net/wiki/Costar_replacement_controllers
it seems correct.
Bathroom Epiphanies
bpiphany is the owner and designer of Bathroom Epiphanies.
He is based in Sweden and creates several controller boards as a swappable component for some off the shelf keyboards.