Sorry probably wasn’t very clear. We want to replace the old telewest connection box for a new one. Can we buy those anywhere?
Is the phone socket your only telephone connection in your home? If so, that would be your master socket. In theory, it should be VM modifying that particular socket.
Also worth keeping in mind that at some point (probably sooner rather than later) VM will switch your phone connection from a master/wall socket to a 21CV phone connection from the back of the hub. At that point you would need your phone wiring modifying anyway to link your alarm connection from the phone socket on the back of the VM hub. You may end up swapping the socket now, only to have to make further modifications at some point in the near future.