As John L correctly states, there should be manufacturer's plates to tell you the information, especially of the van. If it is an ALKO chassis then there is an ALKO plate in the middle of the axle casing. Car plates often only tell you axle loadings and the maximum train weight, not kerb weight. If any doubt, use a weighbridge. For about 7 pounds it will tell you exactly what your outfit weighs.
I suspect you will be within the legal weights but a 2 litre petrol car is going to eat fuel when towing. Be prepared for consumptions in the low to middle teens, especially as you are unlikely to be able to use 5th gear.