Hi Jeff.
As others have implied, I'd say there is no reason for a Vibroplex to EVER wear out - the loading on the trunion pins is very small, and the contacts are more likely to wear in, than out.
If you look at the video on my site (
MorseBusters - YouTube), you can watch the dit contacts rub on each other - "self wiping." In other words, use keeps them working well. That wiping action does impart some wear - but again, microscopically and very slowly. The small contacts on my 1920's era bugs still work fine. They have decades if not centuries of wear left in them :-)
I don't have any 1905 bugs, but I'm confident the same would hold true. They could have other material failures, of course. But bugs are damaged more by neglect and abuse than use.
The knobs - in particular the older bakelite ones - become friable with age, and break quite easily. I don't know - but that old bakelite might eventually become so friable it would disintegrate when touched. But we're talking many decades - centuries...
Worst perhaps, and what we often see with treasures that pop out of a garage or attic, a key bug oiled "for protection" and put away proceeds to ruin itself in a couple of decades of storage. Oils and greases turn to lacquer over time, because of outgassing, and become quite acidic, and pick up other contaminants from the air and hold them to the metal... It's a slow death, but death.
Even oil used on the bearings - in a misguided effort to remove the negligible friction - outgasses, and over time those deposits can wreck a bug while it sits on a shelf.
The best bet for storage is probably a zip-lock freezer bag. Or maybe one of those vacuum sealers... Yeah, that's it. A vacuum-sealed bag filled with a bug. Fun to open that time capsule someday :-)
73 Chris NW6V