I was contacted by several individuals noting that in fact a fifth collectible had been released by Disney and that it is still available through DisneyShopping.com:
Title: “To The Briar Patch” Harmony Kingdom Box
Description: That wily Brer Fox is up to no good–again! Lift open Brer Bear and you’ll find a knapsack quicker than you can say zip a dee doo dah! Made of crushed marble tumbled to create a fine patina. Imported. Certificate of Authenticity. Limited Edition of 500. (Item #96258) $99.95