I don't know what a Model T weighs. I would guess combined T and trailer at maybe 3500 to 4000 pounds depending on your trailer and what model the T happens to be.
In my neighborhood the law requires trailer brakes at I think 3000 pounds, or the trailer weight exceeding some fraction of the towing vehicles weight. I don't know how much those rules vary state to state and certainly could not say what they are in the land of our northern neighbors.
Irrespective of the rules, my opinion is with or without trailer brakes that the most important towing capacity issue is brakes. Just because the people who make the rules say something is so sure doesn't make it so...
