Disco 2 central locking fault

Hi there. Hope this is the right place. I've got a 2001 Disco 2 td5. I need to order a second hand central locking roof control box (bcu). Not right terminology! I notice the part numbers in adverts seem to differ from mine. What should I get? I enclose a photo of the faulty one. Thanks for your help. Johnny

Yeah there were a couple of types then they were superceded by YWY00080. I bought one of those as it means its slightly newer, if buying second hand