Hello Steve, thanks for responding.
I can appreciate the point you're making, but in this case there isn't much difference between the earliest manuscripts and the original manuscript.
This is particularly so given the testimony of Papias, the one recorded as being John's scribe. If John's own scribe affirms the passage, we indeed have a window into the contents of the original manuscript.
Further, Jerome, writing from the fourth century, used only the earliest manuscripts available at the time. He included the passage.