I made one visit to Bolivia in July 1974. A Central American Rail Tours group led George Werner and myself traveled from Argentina to La Paz. Originally we had planned to visit the Teresa Cristina in Brazil, but it was washed out by torrential rains. So at the last minute we substituted a train ride from Argentina to La Paz.
We boarded the through Pan-American at Jujuy, Argentina, but when we arrived at the border we were informed the Bolivian connection had been cancelled due to a washout. We moved the group to the Hotel Crystal and George and I quickly made a deal with the local bus company for a busitution to La Paz, with an overnight stop at Potosi. We were able to photograph some steam switching at Villazon, and we made a side trip to the steam terminal at Uyuni for a few more pix. Sadly there was no more mainline steam around La Paz, but we did find an shay switching the passenger station, and the steeply graded electric line to Viacha was still operating.