There are a few details lacking in their description, one that would be helpful, would be to have the measurement of the cable length and a few other specifications included, to help identify the part when none of the other numbers really are helpful. Or when some of them are missing.
Short of actually having the 12" and 14" iBooks set side by side with their keyboards partially pulled aside, and then a picture of the differences stated in text overlay, so one could guess later (with only one iBook present, or just the keyboard) what you actually have. Since there are several optional part numbers suggested to be a suitable replacement keyboard, even at welovemacs, one may actually have to give the supplier a call and ask for details... and had an older one you needed to match.
Some of the online sales adverts for these parts are also lacking in details; so if the parts were derived from a take-apart, the seller should be smart enough to retain basic configuation info of the host computer and include that in their posted information, to avoid mistakes and to save time or expense of all followers.
Glad to hear you found some matching information.
Good luck & happy computing! 🙂