Re: Was Hartnell first?
Since the faces in The Brain Of Morbius were abiguous they can viewed either way, even though it was the intent of Terrence Dicks from what I understand that the faces were the Doctor's own. However I don't know how much weight that carries since Robert Holmes rewrote the story.
FWIW, Terrance Dicks's book write-up of Morbius fudges the issue: "The debonair white-haired features of the Doctor as Sarah had first known him... Yet another Doctor appeared on teh screen - a dark haired little man with a whimsical expression. Then another face... a proud-looking old man. Sarah had a confused impression of even more faces on the screen." (I've skipped copying the bits that are simply quoting the dialogue as onscreen).
"Some days are better than others. They say that where I come from."
"Loudly, I imagine, on the day you left."
(Blake's 7 - Rumours of Death)