Good people this was the hobby answer
"Thank you for your E-Mail.
After checking of the chassis number we can see that your caravan has a few extras.
Insofar you have a reduced remaining loading for your Caravan.
There is a possibilities to increase the weight to 1500 kg (but only with technical changes).
Please contact your responsible dealer for clearing your matter. A directly handling of here is not possible."
Now i will contact the dealer to see how much it will cost to me.
"Thank you for your E-Mail.
After checking of the chassis number we can see that your caravan has a few extras.
Insofar you have a reduced remaining loading for your Caravan.
There is a possibilities to increase the weight to 1500 kg (but only with technical changes).
Please contact your responsible dealer for clearing your matter. A directly handling of here is not possible."
Now i will contact the dealer to see how much it will cost to me.