Update:
Sadly, Crow never appeared with a family in tow, and gradually he stopped taking food to the nest. We think the young were probably taken by predators while he was out foraging.
Happily, Crow has now appeared with a new Mrs Crow, showing her the ropes of the best places to pinch hen and sheep food, sitting in the same tall tree he and Hoody used as their lookout, and collecting worms and larvae from the same pastures. So just perhaps they will breed together and we will get a family this year