As far as I know only Chester and Cotswold Wildlife park now have Great Indian hornbills, although 10-15 years ago Colchester, Marwell, London, (maybe even Rode?) and Ventnor Bird Gardens all kept this species.
Does London not have Great Indian Hornbills anymore.
Rode probably had them in the past though I can't remember seeing them there.
Paulton's Park definately had Rhinoceros Hornbills in approximately 1991/2 but I've never been since...