Hutch, that is an interesting travelogue. It does speak to similarities and differences of electrical systems all over the planet.
Although not unique to Siberia, looking at your socket/receptacle pictures and their round pins finally clicked with some electrical components I’ve seen in catalogs for years—not imagining how they would be used. Being from an area where plug/sockets have flat blades, use of voltmeter “lantern” probes makes very good sense in most other parts of the world—for they must fit nicely into most outlets.
[Hope this doesn’t goof up page formatting too badly.]