I must say that my experience with KLM UK reservations has always been VERY different. Sure, you occasionally get an inexperienced res agent who does know how to get elite seats on NW metal (they don't seem to show spontaneously on their system unless the agent enters some extra command). However, whenever I have come across such an agent, just get the available seat maps off nwa.com and specify available seats and they'll look into it. And, hey presto, they speak to their supervisors and/or more experienced colleagues, and they'll get the seats for you.
Whereas my experiences with AMS based staff has not been that great, res people at Norwich have always come up trumps.