This loco has been superbly built in what I would call a robust style, around a very powerful Bonds type motor/gearbox unit. The pickups are wiper blades to the backs of the wheels. The wheels are of cast iron construction with fine spokes and are slightly thicker than fine scale. They negotiate Peco fine scale track and points well. The Poachers test track at Lincoln https://www.7mmloco.co.uk/poachers/ was built using Peco track and this loco can fly around there with six blood and custards in tow, no problem.
One hundred and ninety five engines of these Henry Fowler developed locos were built by the LMS. Adding to the 45 similar locos that had been designed by Richard Deeley and built by the Midland Railway, to which they were almost identical. The most obvious difference is that the driving wheel diameter was reduced from 7 ft 0 in on the Midland locomotive to 6 ft 9 in on the LMS version. The Deeley locos had been developed from a 1902 design of Samuel Johnson which had a three cylinder compound arrangement. This had a layout of one high-pressure cylinder inside the frames, and two low-pressure outside frame cylinders. The modelled loco, number 41186 being one of the Vulcan Foundry built engines built in 1927 and the class were still being built at Derby works in 1932. A long and complicated building history, but they got there in the end. The class were withdrawn between 1952 and 1961.