Back in the days before alkyd chemistry was invented colored oils (pigmented boiled linseed oil) went under the highly technical name 'paint.'
But my first look at that body says black milk paint (more likely an acrylic substitute) followed by some sort of flat/satin sealer.
Milk paints are actually pretty cool, they go on super thin, adhere like nothing else, but can also be sanded, and if you are into the relic look they wear really nicely. They must be applied to bare wood though, or on top of other milk paint, but work lousy on top of anything else.
If you like the look but don't want the wear then you seal the stuff with a modern acrylic clear coat.
