A bit of a status update. A few technical issue with the printer (ie: a broken extruder head) resulted in me only getting the stuff printed the night before last.
Here's a "draft" print being done. The "spaces" in the sidewalls are just so that filament was not wasted as this was purely to see that the sizes were all correct.
There was also an issue with my design.
If you look at my original CAD design, there were supposed to be two triangles and a polygon on the one side where the relay socket was supposed to fit snuggly. The problem with my design was that I did not perform the "union" of these elements close enough to the other elements. ie: The printer did not see them as being attached anywhere. As such, my boxes came out near perfect, but missing the artefacts on the one side.
I have tested the fit of the relay sockets, and despite the fact that the design is slightly different from the original plan, everything still fits perfectly, and I'm happy with the outcome. Will probably get around to fitting everything the weekend, as it is a busy work week for me.