Not the thread topic, but sensor corrosion was a good bet on most MM cameras - always just a matter of time and actually, infrequent use!
In retrospect, Leica could have sent a recall notice to all owners who registered their cameras and to the websites/forums, such as this one, frequented by Leica MM users.
A recall of these cameras for sensor replacement would have been the best policy. For owners that wished to check their sensors, the process is not difficult - it just needed to be communicated earlier to the owners! If you can photograph a wall, you can check a sensor for corrosion. Eventually the instructions were available on-line, but it took a trade-in/upgrade program (for another Leica!) to make this happen.
It could have been handled better IMO.