have a look on your chasssis plate on the car mate, it will tell you the max train weight which is the total weight including car,trailer and load then you can work it out from there, you need to find the weight of the trailer and if the trailer has brakes or not but 99% of car trailers do then get the weight of your saph and add it all up, will be close but ive got a 53 plate mondeo and its fine for towing a twin axle trailer with the escort, just a bit sore on the car so i try and get a jeep or pickup where i can

as for your licence im sure thats the right one, im sure the change was in 1999, just go onto DVLA site it tells you all there