I used to have an 80 series std diesel. Done heaps of towing with it. 2.5 t boat 2 t horse float. You wont have any dramas with any camper trailer on the market.
As mentioned above, the tow rating changed in 96 from 2500kgs to 3500kgs with no change to the vehicle at all. So even though yours will only be rated to 2500 it has plenty of reserve.
I will probably get flamed for this, but it would be a lot safer to tow heavy weights with your truck than any of the new breed of 'mid weight" dual cabs on the market!
Very good truck. Just the more you tow, the longer it will take to get there! They are a slow old bus, with the 1HZ. But they will go forever.