The rear side normally has a diaphragm with no gold on it.
The K 47fet has only ever been used in two microphone models, neither of which has been a real world-beater in terms of sales. So it's not entirely surprising if replacement capsules of this type might sometimes carry a higher retail price tag than the K 47/49, which costs somewhat more to manufacture but is needed more often.
Correct, the rear side of the K47fet has no wire attached to the eyelet held down by the center screw, but is otherwise ready to go.