SFEX 4204 was an MLW C-424 purchased from Canadian Pacific. It was originally CP 4204, built in March 1965 by the Montreal Locomotive Works. It worked for CP for many years until it was acquired by the Ottawa Central Railway. It went to IRSI in Moncton on May 2 2004. It stayed there all summer and finally left in early November, lettered SFEX.
4204 has an alternator from a retired CP 4500 series C630 or M630. It was shipped to the DRS shops in Nova Scotia in January 2007 for electrical work.