I assume the Britannia at Kemble could taxy, although I haven't heard any news of it ever doing that.
As for the VC10, I can't see any reason why CAF's example couldn't be taxied. If it is to be handed-over in flying condition (one assumes that there will be no interest in removing parts for an obsolete type) then there should be no reason why it could not move under its own power again.
I agree that the sound of a VC10 on the ground is quite distinctive. I fondly remember standing on St.Mawgan's control tower balcony, watching a No.10 Squadron VC10 manoeuvre into the West Pan and I can still hear those Conways whining to this day!