What lies behind

Behind the Z-Axis platform there is this gap. This gap does not go through. It is basically a very thin, very inaccessible storage for lost stuff. And the thing is occasionally when using my 5-in-1 tool to pry up a part, particularly prints that are only a few layers thick like stopped failures, they pop up, flip back, and disappears. I hadn't figured out where they went until this week. Unfortunately it is too thin and too inaccessible to get stuff out with a tool, let alone see what's back there. The only thing I could do was unplug and unload my replicator, flip the whole thing over and shake.

Here's what was hiding there. Wow, that failed joint print was from a while ago.

I could print someting to close that off but I'm concerned because I don't know exactly where the z-limited switch interacts with the z-axis platform. I want to fix this, but I need to go about it carefully.