[Ian McCallum]

I may have my old drawing, not sure. The map case is however common to all the HU family so anyone who has one fitted can supply exact dimension. I have attached 3 photos that will give you a good idea and from which you could scale your needs if necessary. top folds towards the back and is a continuous type piano hinges which allows the front to drop down which again is held in place by a continuous piano type hinge and leaves a retained area to hold in the maps.
Ignore the map table which is shown as this is unique to the HUW.