Southern Railway: https://en.wikipedia.org/wiki/Southern_Railway_(UK)
This model is designed from drawings published in "Historic Carriage Drawings, Vol 3, Non passenger coaching stock" by Peter Tatlow
It's the 'Blue Book' (ISBN 1-8998 16-09-7). Also consulted were, photographs available on-line from many sources supplemented by viewing vans where I could.
It doesn't look like it could ever be real... Copyright concerns mean I am not posting a picture of the prototype, but it really did exist!
This is the model for a SECR-designed and SECR/SR-built van to Diagram 1426. Several of these vans were rebuilt with ventilated sides for use on London-Dover-Folkestone fruit traffic, subsequently labelled as Diagram 1427. This van survived into BR revenue-earning service, and several becoming departmental vans in the black livery.
There were both unfitted and vacuum fitted versions, and a brake cylinder has been provided for the latter. You will need to source vacuum pipes yourself, however!
Please note a few caveats:
Model of the SER Clapboard Waiting Shelter based on the drawing by Brian Hart in the Elham Valley Railway book.
10mm scale. Slots provide for 1mm clear plastic sheet to be used for window glazing.
10mm scale based on the article in Model Railway Journal