Hello Mauricio,
I am afraid there will be no inexpensive solution for your problem, especially if you intend to restore your U67 to its original sound:
The capsule shown is not a Neumann product, but a David Walker, Canada, copy of a K67 Neumann capsule.
Arguing the merits or demerits of installing such a capsule in a vintage Neumann mic in the first place is not productive here, but few would disagree that the original Neumann sound cannot be obtained with an aftermarket capsule, let alone with one whose diaphragms don't seem to be mechanically stable.
The only remedy to restoring original sound for your mic I see is through purchasing a new or used genuine Neumann K67/870 capsule, and having it professionally installed.