I didn't really think of that did I.
Maybe you could change the bottom of the FPE
playanimineditor=0
to
playanimineditor=1
Then, when the lid is open in the editor, you will be able to see inside the case.
This might work, it might not.
Before you build your game (or test it for that matter) make sure to change playanimineditor back to =0, otherwise, the case will continue to animate in game in a continuous loop, until you get near it and press 'E'.
Cheers
Jay.