It looks to be in great condition. Maybe I'll just keeps it as a collectors item.
I used to run into those at second-hand shops every few months, but haven't seen one in at least a year now. The original AEK is far more desirable, in my opinion, but much less common (there looks to be a really nice one on ebay now for about $80), than the AEK2, but some people feel the opposite.
They will not work without an ADB-to-USB adapter ($25 on ebay) and are very prone to yellowing. I have gotten several with dead switches, but that is not too hard to fix.
Those old Apple PBT keys are the best Alps keys ever made, in my opinion, but the stupid legends and bizarre layout configurations make them hard to use on other boards unless you are OK with a mis-match.