Were it me--I would try to put them in a preservative such as Cosmoline. Below is the generic description of it. They would outlast our lifetime then.
Cosmoline is the genericized trademark for a common class of brown wax-like petroleum-based rust inhibitors, typically conforming to United States Military Standard MIL-C-11796C Class 3. They are viscous when freshly applied, have a slight fluorescence, and solidify over time and exposure to air.