On the DVD closing credits, credits are listed for Mr. Tumnus, Reepicheep, and Dr. Cornelius, although none of these characters appear in this story.
When Prince Caspian appears as his younger self in Aslan's country, Eustace recognizes him immediately, even though this is not the same Prince Caspian Eustace met on the Dawn Treader. The actor is the younger version of Caspian from Book Two. One must assume Sam West was not available for such a small cameo appearance.