I got this T430 in about June of 2013, and it came with a non-backlit keyboard. I know that other T430s have backlit keyboards, but I don't know if they're actually compatible and fully functional with machines that didn't come with them preinstalled.
Could anybody tell me if I would be able to properly use a backlit keyboard on a T430 if it didn't come with a backlit version?
You can interchange your non-backlit keyboard with the backlit version of the keyboard in your Lenovo ThinkPad T430. Backlit and Non-backlit version uses the same connector, therefore they can be interchanged without any problem.
Refer this document and choose the FRU number in your preferred language format.
Note that the keyboards will work straight out of the box and that no drivers or software updates are necessary.