Content editor/admin use: Similar to the one in the "Author Information" tab, add a "translated by" box to the "Translation" tab to credit translators. I'm currently keeping both names under the authored by tab.
This is related to the open translation initiative ticket: Complete primary translations for KobeJET Japanese navigation
All translators/content editors have permission to change the author information of content. Translation authors can change the author to themselves when a new translation is created, as the original and new translation will be recognized as separate pieces of content by the database.