Not much of a mod here, just a couple of bits of info that might be of use :-)
This info is for the ISO version, but since the PCB is the same as the version without the extra key between left shift and Z, I'd wager it applies to that version as well.
First off, the matrix highlighted on the PCB:
I've marked the wire links in white. Note that three lines have diodes in them - that's a neat trick to allow those lines to also power the lock LEDs, saving three pins on the controller chip.
I arbitrarily assigned row and column IDs on the chip:
Column and row marked on each key:
The connector on the back is for a number pad, so apart from the required rows and columns, there's pins for the Num Lock LED (active low) and power:
The numpad keys are assigned as follows:
E0: 9 PgUp
E1: 8 Up
E2: 7 Home
I6: $ <--- non-standard code 0xE049
L0: 3 PgDn
L1: 2 Down
L2: 1 End
L7: 0 Ins
M0: 6 Right
M2: 4 Left
M7: . Del
Just one crossing on the matrix remains unaccounted for, sadly it doesn't produce a unique code and is the same as J6:
H4: \ |
Actually, I did make one small mod... on this particular layout, with the blank key between left shift and Z, the blank key wasn't producing any scan code. It turns out that the switch wasn't connected! In fact, one leg had been bent back deliberately to prevent it functioning! (I have two of these boards, and they both had the same bent leg).
With that fixed, the key produces the 'Europe 2' scan code as expected (that's \ | for UK, < > for DE, etc).
My guess is that they had a large order for US layout boards, which they didn't have the parts for - presumably plates, since the PCB is the same.