How do you "tension" the capsules/membrane? I'm a complete newbie about microphones, I just read Klaus Heyne's original article on germanmasterwork.com about the U67 reissue, where he stated that he measured 10 original Neumann (K87?) capsules on both sides and no 2 were the same. (He also can release the tension to make them more low-rich, akin to the vintage ones as it is believed.)
It's nice that both sides of yours measures this close to each other. Just out of curiosity, do you tension them yourself, by hand, or it's also automated to a tight tolerance at your contractor?