His first official role as the First Doctor was in the recreation of the the 'lost' footage from the original episodes three and four of Planet of Giants for the DVD release (the story was originally written and recorded as a four-parter before being edited down to three episodes), where he acted alongside the story's original stars William Russell and Carole Ann Ford, both of whom were impressed by his impression. (DCOM: Rediscovering the Urge to Live)
He also voiced the character in the Doctor Who television story The Day of the Doctor. To convey the surprise of the classic Doctors' appearances in the story, he was credited as "Voice Over Artist". Writer Steven Moffat jokingly stated that he hired Guilor for the 50th so that the First Doctor would finally say the word "Gallifrey" on screen (although, in actual fact, the First Doctor had said it twice previously in The Five Doctors).
He voiced Doctor Omega using his First Doctor impersonation for an audiobook. This 1906 character is known for his coincidental similarities with the original incarnation of the Doctor especially since Jean-Marc Lofficier's adapted and retold translation, although the audiobook is closer to the original text than Lofficier's edition.
- Kistler, Alan (26 November 2013). "What Just Happened in Doctor Who? The Anniversary Special Explained". Wired. Retrieved 28 November 2013.