So Frank read my previous post about the Phantom unmasking for the first time in history and dropped a line to his buddy Graham Nolan, who drew the Phantom comic strip for several years until 2006. And Nolan replied with this Sunday Phantom strip from October 2003:
The Phantom unmasked! (Gasp!) In his reply, Nolan noted that overseas Phantom fans were very upset with him when this was published. For now, this stands as the earliest record of the mysterious Mr. Walker's* true face.
Many thanks to Frank and Graham for following up on such a silly subject and giving me permission to write about it.
*For "The Ghost Who Walks"