I've got a Telefunken ELA M 251 here, which had come from the original owner, who had it in storage for years. The black lacquer seals are still on the head basket screws, and on the plastic body screw.
Amazingly, this mic seems to have come from the factory with a green-label 6072 tube installed in it. It's very curious, because there are pictures of a 251 on coutant.org, that is just six serial numbers away from this one, that has a white paint GE Five Star 6072.
Fortunately, the mic sounds terrific as is, and it's apparently one of the few green label 6072s that passed AKG standards. Has anybody else ever seen these in sealed 251s?