You do not purchase the material, but the history of the item.I don't really buy that for functional objects. I've restored old Teletype machines, some almost a century old, and provenance is not a big issue.
In fact, because of the way they were maintained, many are not an original set. There are four main components of a Model 15, keyboard, typing unit, base, and motor. All are field-replaceable, and the first two are easily swappable without tools. Maintenance was often a swap, not field repair. The units went back to a repair depot, were repaired, cleaned, and oiled, and then went to another rental customer. Retired machines rarely have the original subunit combo, and nobody cares.