I inserted a micro SD slot and 4 switches into the LCD holder.
The size for the micro SD is: width 26mm / height 8mm / depth 29mm
I use this one: https://amzn.to/2veliPU
The size for the switches is: 20mm x 13mm
I use this switches: https://amzn.to/2AioXCf
For me works "tree support" great fpr this. Only in the micro sd slot was it a bit fumbling to remove.