my first design go easy on me. work in progress, I will fine tune over time. all screws used are 2.5mm diameter 5mm length using bread board jumper cables to connect pi to the hat without soldering and a micro usb pcb to power the pi and allow the usb to pluggin at the rear of the case. the mem card is also removable on the right side so once assembled unless an internal part goes wrong you wont need to pull the box apart.
(if you already have a OLED screen fitted to your HAT the stand off points are enough that you do NOT need to remove the OLED screen it can stay where it is)
power from the micro usb socket on the back pannel goto pin 2 for 5v and pin 6 for ground on the GPIO on either the pi or the hat ( I attached mine to the underside of the pi )
screen sizes for upto 4.5" will eventualy be added for the front plates as i get the screens in house or can borrow them localy for size testing
Jumper wires Female to Male 30cm
Micro USB to Dip adapter for rear usb power socket
2.5mm Dia x 5mm screw
Screen file used in pictures on my drop box below
Future goals to add x2 18650 batts, a voltage stepper to get the 5v ouput for the pi and a charge circuit so it can go mobile simply by unplugging the rear usb cable and taking it with you as there is plenty of space to expand the build further.