240 Wagon + Auto appears to have a GVM of 1950kg. Check the actual tare weight as the tow bar and auto add up to basic tare that is specified on the paperwork I can find (1359kg for an auto wagon + 18kg for the towbar, so a total of 1378kg). That leaves you 572kg of load in the car.
This is made up of a maximum axle load 835kg (front) and 1160kg (rear) (note that they add up to more than the GVM, so you need to make sure you've got it right)
The maximum towing capacity is 1500kg, and the max ball weight is 100kg
There is no Gross Combined Mass (GCM), specified so you're OK there.
So, moving forward....
If the caravan weighs a maximum of 1350kg (The ATM is the maximum that the caravan can weigh, there's no "If I don't go over".... it's the maximum it can weigh.) which is under the 1500kg tow limit of a 240. The max ball weight is 100kg, and will be transferred to your car's load (and the rear axle in particular) which takes the car load down to 472kg, so about 4 of me and the beer fridge + dog it would be loaded up....
The 150kg difference between what you are planning to tow and the max, I would not worry about too much; this is from the era when towing limits were realistic, rather than now where they're optimistic - for example, my 1992 4Runner also had a 1500kg tow limit (and 400kg unbraked), whilst my 1994 Land Cruiser has a 2500kg limit. Personally, I run electric brakes on my 750kg trailer (i got it when I had my 4Runner), and they are nice to be able to control the trailer and get quick response at slow speeds; overruns can be a bit doughy at low speeds, especially if the trailer is light.
Make sure you get the ball weight set right (between 75kg and 100kg would be my range), the weight is low and concentrated around the trailer axle, and that you haven't used heavy things at the back of the trailer to bring the ball weight down (see-saw style) as that can really induce sway.