The Class 501s were introduced in 1957 to replace the LNWR Oerlikon sets. They operated the LM Region Suburban services in London, out of the Euston and Broad Street termini. The services were subject to considerable contraction during their lifetime, some of the units were withdrawn in the 60s and 70s but the majority survived until 1985, when they were replaced by Class 313s and Class 416 EPBs.
My Thanks to WEN for allowing me to use his original Suburban MK1 meshes.