The manufactured PCB arrived with the assembled SMT parts in place. The PCB is made of an FR4-Standard Tg 130-140C, 1.6mm 2-layer board. Its size is 118mm x 168mm.
The remaining THT assembly is straightforward.
Most critically, the PCB size fits into the enclosure with the exact right amount of tolerance. The first issue to note is that the mounting hole sizes are too small. The enclosure requires M4 screws. Thanks to sufficient clearance, manual drilling with 4mm fixed it.
This is what the parts look like before assembly. The full material list is available in Github.