Sorry for late reply...
I've made this case from aluminum angle bars:
It was a little bit tricky to get exact fit with the LCD and all the PCB's.
But it seems that I had a big luck, and all parts fit nicely
Now, let's go to the inner side
The boards are assembled together with the LCD's stock screws and simply put into the top part of the case:
The connection between RPi and the custom board is made with two connectors, flat cable and some soldering:
That wasn't an easy task to connect all the pins to the cable
This little black board is PCM5102 DAC. It is marked 'CJMCU-5102'.
The 5V step-down converter accepts wide range of input voltages and provides stable power to Raspberry Pi.