No, they aren't identical because as you say "one had some time go by". Most things are used, and with use, an object is changed. Secondly, "exactly the same methods" is questionable, depending on how old an object is. You can't just make things by exactly the same methods in many cases. And finally, there are entire civilizations that have been wiped out, so even an exact replica of something created by a member of such a society could not be recreated today. Good article though.