BR 4MT 4-6-0 No 75055 with the 3.5pm Bedford (MR)-St Pancras at Elstree & Borehamwood on 9 May 1959.
The leading coach is a 30 year old LMS Period 1 all third. The Rolls Royce DMUs would come in early 1960 and it would soon all change on the southern end of the MML.

Photo: K.L. Cook / Rail Archive Stephenson