I found a relatively cheap 5" LCD on Aliexpress
(Link to product: https://www.aliexpress.com/item/4001197186380.html )
It looks fine, although it is not perfect.
So far I observed few problems with it:
I was worried about the thin ribbon cable so I designed the case right after getting it. Might think about upgrades/new cases/other projects with this LCD in the future.
Instructions:
No supports needed, infill/layer height up to your liking (0.3 will work fine), maybe use more perimeters for the screw holes.
Use short M3 screws to mount the PCB to the adapter, then use bit longer M3 screws to mount the adapter to the front part of the case.
Use two M3 screws to moung the OSD Keyboard to the back of the case, then carefully assemble both parts together (you guessed - with more M3 screws).
Watch out for the OSD cable, might need to carefully bend it and lay in free space, if will push back of the case if it gets between the back cover and PCB.
The author hasn't provided the model origin yet.