where the locals and soldiers did lots of the wiring.
That's what it looks like...
Looking at the cable that enters from the left I'd guess they used blue as their neutral.
Oh well, the panel with plaster doesn't look much worse than most panels here do after 2 or 3 different persons have worked on them. Those single-row din-rail panels have extremely little wiring space, so even most new installations don't look much better than that, apart from the flying "TNT" splices. Mine certainly doesn't. You'd have to put _really_ much effort into wiring such a panel neat and nicely.