Created a spacer so I could add GPIO headers and a bit more space for larger battery.
Short M2 screws needed to hold the spacer on. Make sure there is enough clearance as the front cover screws use the same thread. You can probably cut/file down the stock screws if you want.
M2.5 screw inserts get glued into back case. I made sure that they are sitting flush with the inside face so the screw would be recessed in.
I have added some other untested options that use a 3d printed rear cover instead of the stock one which also use M2.5 screws.
The author marked this model as their own original creation.