Southern Pacific M-4 class 2-6-0 Mogul, built for the SP by Cooke and AlCo-Schenectady. 
115 units built, numbering 1615-1719.

Anthony Sava was the original (as far as I know) designer of more than a few elements on
this model, as was Benn Coifman.

For questions and comments, I can be reached at:
tbunts91 (at) yahoo.com