Should a restored instrument look like new?  Yes, it certainly should.
Over restored?  No.  I think they should look like they were just ready
to be shipped from the factory when they were first built.

The new book by Art Reblitz seems to showcase the upper crust of the
mechanical instruments that have survived, some probably over restored.
They are beautiful pictures.

More interesting to me is the wealth of information available in this
book.  I recommend it to anyone.

Jon Guy