Here's a good sentence to try the pronoun form on.  I took it from a
handbook--
 
     The jury was astonished when the witness suddenly confessed that
the murderer was none other than he.
 
I see "than" here as a preposition, substituting for "except" or "but."
If it is, then on objective case is called for--but the "he" has already
been identified as the speaker, so "himself" might be a better choice.
"Than" is not a conjunction here, for the "he" is not the subject of an
understood verb.
 
Responses?