As I said last week, here is another 100 class locomotive, but it is in the P.R.R. Class 113 - 124 according to the book Diagrams and Photographs of Railroad Equipment Used to Construct the Panama Canal - 1881 - 1914.  In the book descriptions there really isn't any difference, except for the class range of numbering.

This week's photo shows P.R.R. 120 heading out pulling a load of passenger cars at Colon,