I did read (on AB, I think) that the BBC have a new actress who will play Clarrie Grundy. The original actress has retired, if I remember correctly. My guess - for what it's worth - is that the script writers are leaving it as long as possible between the last appearance of the previous actress and the first appearance of the new one, so that listeners won't notice any slight difference in the voices. As for Tony and his immediate family, I don't know what's happened to them. The script writers are probably giving them a rest, whilst giving more exposure to other characters.