In February 1969 the London Midland Region added set numbers as a means of controlling and maintaining the DMU fleet efficiently.
Carrying set number LT330 is a later Derby Lightweight (M56484 closest) seen in New Mills Central Station in August 1969 with a Cravens unit. Pete LG99.
The initial set numbers issued to the London Midland Region DMUs were:
|Depot||Prefix||D.P.U.||Single Cars||2 Car MC + MC||2 Car MC + DT||3 Car Low Density||3 Car High Density||4 Car Sets|
Note that the number 176 was issued twice, to Accrington and Cricklewood (as per the document page 7 / Appendix A).