Tony Riley. They were a batch done to special order last year.
I have 4 to build.
Not sure if he's going to do any more - but Andy at Woodbury Models has some similar, although laser cut.
Tony Riley does kits in G1 and a few of us Gauge three-ers persuaded him to do a Midland van.
They have scored plywood sides and ends, all the other timbers are machined hardwood, so applying the outer framing and cutting the end angles is quite tedious, but looks the part.
The four I am building are D353, I will be using Williams Models running gear.