It would have been translated once, directly from the Gnostic gospels that were found. But I’m not sure why that matters since they would be scholarly translations because they were found in the mid-20th century and the important thing is discovering what the Gnostics believed, meaning an accurate translation would be necessary.
I think you’re confusing the Gnostic gospels with something like the King James Bible. It’s totally different. We only knew what the Gnostics believed from secondary sources until the Gnostic gospels were discovered.