Replacing broken keys -- is it possible?

This is a great description/teardown. One question: the "L" key on my keyboard came off. I tried to replace it following the insights in the teardown (realize teardowns are not a repair guide!) but not sure if it's possible and wondered your opinion. The part that came off was the plastic cap that has the letter printed on it. The rubbery thing underneath (the piece that holds the key suspended over the button, so to speak) was still in place, so I pried that off with a sharp point. Then tried to join the plastic cap to the rubbery piece, but with no luck. In fact, I broke the little plastic tabs on the back of the plastic cap trying -- so pretty sure it's destroyed for good. Question is, any idea what I did wrong? Is this situation fixable? In your teardown, did you manage to salvage a working "L" cap that coud be purchased? Thanks again for a great explication of this otherwise pretty good piece of hardware. Kevin