Maybe I was a little misled by how tiny this case is. Originally designed for the Ethernet shield, I don't think anything extra was supposed to go in. The little battery cover "looks" like a standard 9v size, but it's actually 1/4" smaller than the battery itself. I dislike not having case screws after trimming 4 of the 5 plastic posts, but it fits...

The Ethernet module is solid and tight, and I may tape the edges from having it pop open, but I'm happy how it turned out.

I'll follow-up with a demo video tomorrow!