My brother came to visit. He brought a loco, and thus it became the first visiting loco on my line

This is a Regner Konrad, kit-built loco. It’s a geared, oscillating-cylinder loco. The revering lever is on top of the cylinder, and the cylinder drives a flywheel, and the gearing, which makes it quite a smooth (and realistically slow) runner. The regulator is in the cab. This is about as simple as it gets.