I don't think towbars even had ratings back then, you just towed what you could, or needed to.

Judging by modern standards, I wouldn't put more than about 700-750 kg behind one.

also largely depends on how careful you are. my type 3 towed an XD falcon(!) 10km's through dozens of traffic lights (tied to one bumper bar mount)... and no damage.

don't try this at home, it was a genuine emergency.

My bug's Owner's manual says "max towing weight for trailers without brakes - 400kg. With brakes - 500kg."

That being said, I have ALWAYS had a towbar on my bug, and I've towed some horrendous loads with it.

Like a measured 1600kg on an unbraked trailer down a very steep hill and then another 20km on the flat. The trailer was very insistent in saying it REALLY wanted to go first down the hill :-) Loads of fun (not) - crawling down in 2nd gear dabbing the brakes to keep it under 20mph, and keeping the trailer behind the car! But on the flat the bug pulled that load just fine - not much acceleration, but you wouldn't expect it with only 53hp (it was a 1500 back then).

I've towed a small caravan all over NSW, and have had to tow my broken Ford home several times - all 3200lb (1450kg) of it. The Ford has never had to tow a bug though :-) My wife thinks it's fun to be towed behind a bug (not) - the Ford NEEDS power steering and power brakes, and with no engine, she got muscles on her muscles.

I take a large load of rubbish down to the dump about every month (1/2 acre yard and a greenfinger's wife!) - probably 1/2 ton or so each load.

Bugs (and type 3s) are tough!

My uncle was telling me the other day about how he towed a broken down Hillman Hunter from Eildon to Dandenong with his '62 1300 beetle! had four people and lots of camping gear in it as well.