Noted today at East Somerset Railway, Cranmore was the above. This I believe started life as BR CAR Brake Van, but has at some point had it's bodywork removed. The chassis is now fitted with a HIAB style crane, stabilisers and counterweight on one end, and a weed spray tank on the other. The middle section has enclosed safety railings and I suspect can carry materials. I have no idea how long this has been like this but a photo is being uploaded if anyone is interested.
East Somerset Railway Works Wagon - DB954896 - Preservation - Forum
East Somerset Railway Works Wagon - DB954896
Been like it since March 2012 apparently.