This design was adopted as the standard goods engine for the LMS after grouping, with several hundred examples being built.
Bachmanns' model features a motor carefully hidden inside the firebox and boiler powering the locomotive driving wheels and carefully designed tooling able to recreate many of the variations which occured between build batches and over the working lives of individual locomoitves. In the case of the 4Fs this included a right-hand driving position on the Midland built engines changing to the LMS standard left hand position. Era 2.