The RFIRT is still in operation, but unfortunately with imported second-hand diesels.
Steam designer L. D. Porta of Argentina, who has worked to improve steam locomotives around the world (and who worked on the ACE 3000 project) was the manager of this railway for several years in the early 60's. He instituted improvements to these locomotives which greatly improved their performance. For more information on these engines, see my webpage at the link below.
Good Steaming,
Hugh Odom