Suggestions on securing these?

[jedimasta]

Anyone have tried and true solutions for securing parts together? I built my jank cabinet in two pieces: the playfield "box" and the backglass "box". The backglass stands on the flat part of the table similar to how those behind-the-toilet shelves do, but it's a bit top heavy and my floor isn't exactly level, so I'm looking for suggestions on how to attach the two while still being able to detach them when necessary.

 

My wife's idea was to use a sliding door lock, like you'd find on a bathroom stall, so I'm gonna look into that, but figured someone here had probably already done it and I don't wanna reinvent the wheel.

Edited April 10 by jedimasta
Forgot photo