I've now been able to model in the photovoltaic cell, which is protected by a 1mm thick window.

I've also brought the motor in 2mm, as well as swapped which chain goes where. As you can see in the below image, the bottom chain goes to the inside now.

I'm still going to need to tweak the paths slightly because I'm 0.1mm off (and that's the reason why the balls look slightly misaligned). Additionally, I'm worried that it might not be physically possible to install the chain for some reason in this configuration. I've increased the amount of teeth on the pulley from 9 to 12 (in an effort to blance the paths).

The LCD looks like this with the change.