This does not make much sense to me. Booked a fairly expensive ticket, two months ago, FB Gold and they cannot find a seat during that time!
In any case you should push KLM and remind them of their EU obligations and time frame. KLM is not as good as AF regarding compensation.
You are owed 75% of that segment. There is always some interpretation regarding the base amount. You could argue that your Denmark-KUL is cheaper than AMS-KUL. Hence you should get 75% of 2 100.
Frankly, I don't understand why additional goodwill gesture is expected, this is already a nice gesture (if KL oblige).