Hi, Eric. This may not be a lot of use to you, but may give you some idea of possible weights. We used to have a 1987 Trophy Agrarian 4/6, a single axle van. This had an unladen weight of 15.3 cwt with a Maximum Gross Weight of 21.6 cwt. In the sales brochure I have for this, there is also listed an Agrarian 4 de-luxe, described as 'Twin Wheel', which I take to be twin axle - the unladen weight of this is given as 18.34 cwt with a MGW of 23.57 cwt. By today's standards, these are all pretty lightweight vans, but you don't say what year yours is.
Enjoy your 'van - we loved ours!