Good one. This is something that can be done with any ADB or other old mechanical non-compatible keyboard. This is the first page completely describing the necessary steps (Chimera's steampunk mod was close but I missed the cutting of the original pcb traces. Might have been bad reading).
There is another Apple Adjustable mod
here. Using a HHKB Lite 2 as a donor adds a USB hub and has the F keys on the number keys.
Someone invite this guy.