Years ago, early '70's, I used to tow a little 2-berth sail-boat with my modified 1955 A30.
The boat and trailer weighed in at a fair bit over a ton, and the A30 I would guess, was not much over 1/2 a ton.
The police never bothered with me, and because the A30 had all the engine, transmission, suspension and brakes etc., from an MG Midget, it pulled it and stopped it, no bother.
The trailer had simple mechanical rod- linked over-run brakes (that I got working really well, but I used to pay a lot of attention to the tow-ball weight, and the position of the boat on the single-axle trailer, because if that thing started to steer me, I'd have been in deep doo-doo.
I took it everywhere, including the road from Birmingham - Oswestry -Knockin - Llanfyllin, and over the Berwens to Bala. (If I've remembered those place names correctly).
Never had an issue...