As I said without an actor actually playing a role, why bother?
If we could find a amateur actor who looked right and we could write some story advancing dialogue and actions which could seemlessly be dropped into the footage, Tarkin in ROTS would make sense (in fact he is such a major player in ANH you'd have thought he'd been in all of them instead of weird alien guy no1 or spooky alien lady no2).
Unless he's actually doing something it would be better to lose him.