First, the 'a magma war drake' turned for me twice when nothing else would. - I have a SS if its needed where you can see the skellie beating a magma war drake and thekill shot is on a voidsoull.
Second, yes it was asked sometime back but, I came here today looking for this location, so.. the war drakes are in the rock valley directly in front of the alliance side of the cave entrance to the DoN Broodlands stuff -- far north part of map right in front and in between the cave entrances.
Hope this helps any others that may re visit this quest