Hi sorry to crash your thread.
I was recently given a brera key buy a friend which was broken where the release button was. That area was missing and the complete head had most of the electroplating missing, it also had some internal damage where the roll pin was removed.
I managed to rebuild the broken / missing part complete with hole for button and slight doming for button to fit in.
I then moulded and cast the item in a white metal high strength zinc alloy, the result was good, unfortunately the area which I rebuild failed during the moulding process and collapsed inwards slightly
I have attached photos of the castings straight from the mould.
I now trying to obtain a similar key head for copying.
If anyone can help please contact me, I am based in the uk.
I am personally no longer involved in this project as my supplier backed out in the end. The one test key that I have been using has not faired well either. The white metal / zinc plate process may be strong but it has suffered exactly the same fate as the plastic one in terms of the plating wearing off where the ring constantly rubs.