The empty weight of a basic 535 was 1020kg. This excluded extras such as spare wheel, battery, sprung upholstery etc. If you look at your owners manual you should find a list of the weights for extra fittings and you will be surprised at what they include and how they soon add up. If you visit the configurator page of the Eriba website then you'll also be able to get a good idea of what these items were and weights. Yes this would be for a 2025 van, but weights have changed very little.
Regarding the weights plate, you have the 1300kg model. The 100kg refers to the maximum load the hitch can take. This is probably immaterial as most cars generally have a max tow bar load of 78 to 80kg.
I think you may find the attached weights sheet useful, one for my now sold 2017 Triton 430 and the other for my current 2022 Feeling 425. As I said above, you will be surprised at the weights.
Colin