I would say that "dry weight'
should be the weight of the complete camper, minus supplies (food, clothing, bedding, hoses, awning), water, and propane.
But I think that in the fiberglass trailer world (with some brands more than others), lightness and "towable by a small car" were/are very good sales tools. As such, I think that sometimes "dry weight" meant the most basic trailer, devoid of 3-way refrigerator, battery, propane tanks, and etc. Meaning, for example, that very few actual 13-ers would be the fabled 995 lbs. on any real-world camping trip.
To me this means that if one is on the edge with towing capacity, there's no way to know for sure but to weigh each individual trailer on a scale; but if one must assume, better to assume on the heavy side (say, 1500# or so for a basic 13-er Boler type). But putting a number on it with a scale is best.
Of course now we're all curious what your Perris Pacer
really weighs