> Dsatz says caps sitting unused on the shelf in their original cases can lose their matching over time.. So any cap that looks beat up would certainly need re-certification by schoeps in order to be verified 100%.
DSatz says that as far as I (he) can find out, there just isn't any way to predict the performance of an older capsule whether it's been beaten up or not. I have one MK 41 capsule that I accidentally dropped six feet onto concrete, which I sent back to the factory right away for checkout but it seemingly hadn't been affected at all. I've also had capsules which lived a nice peaceful life for 30+ years, but were out of spec at the end of all that time; they were rebuilt at the factory and sound wonderful today. (In fact that pair of capsules was a rather poor match at first, and came out of the rebuilding process matching quite a bit more closely than before.)
That's just my personal experience, but I've also tried to quiz the head of quality control and customer service at Schoeps about this, and he essentially denies that there are any readily observable patterns. It's not like "the pressure gradient capsules lose their tension over time, the bass response starts to droop and the cardioid pattern becomes more like the shape of a three-cornered hat"--instead he told me that things simply change, sometimes more than others, not in predictable ways. I'm paraphrasing heavily and he was telling me all this in German to begin with, but that's more or less the message I got.
--best regards