Great summary Jeff. Wonderful show with the peerless Joan Hickson, if you read any of the books, you see Joan in the prose, my favourite is Nemesis. The films have a nice opening theme and look fantastic on blu ray.
I haven't caught up with the Sister Boniface series, currently watching FB season 10, although with some of the previous regular cast gone, I think the show should finish.
Inspector Morse is probably the high water mark of British mystery television, and Endeavour is also very good with Shaun...