Print this with latest cura (with arachne engine), 0.5mm width, 0.2mm layer height and perfect bed leveling is required for colon to look good (the led windows are only one layer thick)

The PCB can warm up so I suggest to print with PETG. Personally used Prusa Galaxy Black PETG and it looks beautiful. The little particles hide any imperfections.

If printed correctly on a well adjusted printer, everything should snap together nicely and tightly. I also suggest to buy little silicon feet so the clock doesn't slide around :)