"Perfect" has many meanings.
The meaning that causes most of the logical problems, where nothing can ever go wrong, is simply not a meaningful concept. Achieving this isn't a matter of making a single perfect widget, it requires something like controlling the universe. The apparently trivial problem with wear and tear in the sense we're used to is just an example of an interaction between the machine and its environment. Eventually that environment will be destroyed in a supernova or swallowed by a black hole, and that's the end of it. It's pretty extreme wear and tear, but that's essentially what it is.
A more useful concept of "perfect" is something like "as good as possible given the limits of what can be realized." It's perhaps not as satisfying, but it doesn't create the paradoxes that the more general sense creates. The reason is that the more general sense is simply not consistent with reality. If you insist on using that meaning, then I'd simply say there is no answer to your question because it's pure fantasy.
