This vehicle originally numbered 638 was built by the LMS at Derby in 1927 as a 4 wheeled Milk Tanker to vehicle diagram 24 Lot 1077. Ten years late it was rebuilt to vehicle diagram 1993 as a 6 wheeled Milk Tanker. It then carried the new number M44000
This type of Milk Tanker was used on the S&D and ran in both freight and passenger trains. Indeed there are records to show that this actual vehicle operated over the route.
Once withdrawn from main line service it became a waste oil container at the North London diesel depot Finsbury Park and was given the internal user number 041499. It remained here until the depots closure in 1982 and was subsequently stored at Hornsey.
Some years later it was bought for preservation and moved to Midsomer Norton in 2006. Major restoration took place in 2019. The vacuum brake system has been tested but requires further work before the vehicle can be used in passenger and demonstration freight trains.