Gunpowder vans became remarkably standardised before WW2. The GWR had relatively few new build, finding it easier to convert their Mink wagons. They built a batch of 25 prior to WW2. BR rebuilt some with vacuum brake but the 9ft. wheelbase should have prevented branding as XP (See W105777). The vacuum cylinder appears to be positioned unusually deeply, like the BR wagon conversions. BR retained older Gunpowder vans until the early 1980s, replaced by VEA.