OP here.
If I say so myself -- I killed

Really, presentation went really well. I just removed his content and thanked him for his collaboration.
Some of the comments here have been so interesting. I understand some of the feedback about my boss's original request of this guy basically being "asking a co-exec to do secretarial work." At the risk of too many details for this forum -- I, too, originally thought this was just an admin/IT thing -- and was surprised that another exec was asked (and was given the work.)
But, again, info I didn't include before: the whole point of this presentation was b/c this same exec had *excluded* me from another peer's presentation (that impacted my division) and I found out about it last week.
I suspect that my boss and this exec knew that this presentation needed to "match" up with that presentation…and they were caught-red-handed about not having gotten my participation/input on that presentation. I realized this when one of the exec's edits to *my* presentation was to link to that other presentation. I think it was a CYA on their part.
I think it was sleazy all around.
But, you know what, I edited my presentation back to what it needed to be…presented the hell out of it…rose about it all. Our CEO sat in unexpectedly…so all's well.
And…I'll keep a smile on my face with this exec (and my sneaky boss)…but my memory is long.