You can't generate a return signed with a PIN from the F.8879. PIN is never acceptable for filing a paper return and will, therefore, never appear on the paper copy. If a paper return is to be filed, the IRS has been accepting mechanically printed names of preparers for many years, so you rarely see a preparer signature in wet ink anyway.
Practically, if you must, reprint a the return, sign your name, back-date it, and put a "COPY" stamp over those pages like in the bad-old-days.
Still an AllStar