Why aren't your replicas you? If you take my example, where the replicas have a chemical structure where each molecule is arranged with identical position and momentum to yours (down to the limitations imposed by quantum uncertainty), what scientific test could possibly distinguish it from you?
Would you mind clarifying "with identical position and momentum to yours"? Does this refer to experiences, as well? That would be my guess how to distinguish "me" me from me somewhere else, some sort of psychological test to recall memories and experiences.