We have exactly the same drivers yours were made one day after mine! Although it has to be said the metal work on mine is in better condition. There's less corrosion, the performance will be identical mind you, but it helps to see the copper cap. Your drivers appear to be missing the M6 nut on top of the pole too, that's used to secure the driver from behind, it's possible your nut fell off when the drivers were removed from their respective speakers.
I have attached an image that attempts to show the thin layer of copper between the threaded section and the pole piece beneath it. You can just about see the colour difference. You can also see the presence of the nut.
I have attached an image that attempts to show the thin layer of copper between the threaded section and the pole piece beneath it. You can just about see the colour difference. You can also see the presence of the nut.
