If you need a working U47 and a part really can't be restored or replaced by a historical correct one, replace it by a contemporary, but keep the original - if possible inside the mic so it cannot be lost.
Very often the original part can stay in place disconnected, as new ones are much smaller.
Never reskin - it does not make sense, as a contemporary capsule from Neumann sounds better. Carefully store the original so it cannot be lost, maybe later someone finds a way to restore it, at least it's there to enhance the value of the mic for a collector.
When soldering near the capsule put a protective cap made of paper over it to prevent drops of hot solder residue to hit it.