Thank you for the list, although I'm looking for a ThinkPad T420 keyboard to perform the classic keyboard mod on my ThinkPad T530... does this website also have a list of the official FRU numbers for the ThinkPad T420? Also, by ISO keyboard (the keyboards that are commonly seen in Europe), I mean the keyboards that have a left Shift key that's smaller than the one at the right and an enter key that is an upside-down L shape, and an ANSI keyboard (the keyboards that are commonly seen in the USA) has an enter key that is a wide rectangle and both Shift keys have the same size. I'm not the best at explaining this, so have a look at two pictures I'm going to link to right here:

ANSI keyboard

ISO keyboard

And here's a whole page that explains everything about ANSI keyboards and ISO keyboards

Edit: I didn't know about this thinkpads.org page before, and they have FRUs for most (if not all) ThinkPads, and I easily found the FRU catalog for the T420 there. There's no need for you to be searching for the T420 FRU catalog for me, thank you.