So funny you mentioned this. I didn't check but i'm not sure if the keys toward the front align with the keys on the back but maybe they do. I shoulda checked. grrr... However, in disassembling yesterday to take those pics, I pulled it out in about the 4 o'clock position and I dropped the key 5-6 times when trying to put it back in.
. It just fell in a small dish right below the opening and I was able to retrieve it with one of those little 4 claw spring-loaded grabber tools. Should also be easy enough to shim the side of the key with a small piece of paper if it's too loose though.