There was an article in the July 2013 edition of "Steam Days" concerning Upminster.  It states that the Midland 0-4-4Ts lasted until 1955 when they were replaced with push-pull fitted N7s and F5s.   Here's a scan from a rather under exposed slide (GAF500 - better suited to Biba adverts than to railway photography) of the dmu working the Romford-Upminster service in December 1974.  E50577, Birmingham RC&W (later class 104).