I don't think any of those are autopen. At least they aren't patterns that I've seen, and I haven't seen any at all in which Grissom signs as Virgil.
However, I don't like the look of the Shepard signature at all. The "S" and the "h" in "Shepard" don't match examples I've seen, and the way the "B" is looped looks strange and unnatural.