Do you know how Alfa weighed the car officially, it will be in the back of the manual normally.
Usually the quoted weight include something like
Half tank or more of fuel , say 35kg
Add on 10kg for lighter wheels,
And 10kg for spare wheel and jack
All other fluids etc must be at service levels, eg water for windscreen full.
This wouldn't include optional extras, I presume skyview is one and would be heavy if you have it.
So, if we had to add the 130kg to your accurate weighbridge figure It would come to 1700kg.
What year is your car? I guess one of the first models?
Does it have skyview?