Of course, there's no reason not to do BoB 20 years earlier in the 1900's. China would be even more disorganized. You have Czarist cossacks, rather than Soviet. And you have the Japanese. And any intrepid Western archaeologists would dress in Edwardian garb, rather than interwar clothing.
Same scenery. Probably the same railroad network.
Probably no airplanes. But hot air balloons with small propeller driven gasoline motors??
The Central Asian tribes would be as restive under Nicholas II, as they were under Lenin.