Since I brought my Filco home from work (in favor of the Realforce
) I figured I would pop the case apart and share pictures of the universal PCB Diatec uses. This is from a Filco MJ2 Ninja purchased around November 2013.
I stand corrected about the layouts it supports, I tried to remember them all but without the board in front of me it was a crap shot. It supports 87 key (ANSI), 88 key (ISO), and 89/91 key (JIS) layouts.
You can see in the pictures below that unused switch posts get their respective through holes filled with solder. I'm not sure why they would do this instead of leaving them empty.