Ask Alys: should I replace my old pear tree?

Our gardening expert has the answerIn our garden is a pear tree that’s at least 30 years old. It is a prolific fruiter but it has rust, and the pears are often damaged or scabby. They drop early, leaving a squishy, wasp-infested nightmare on the ground, or are unappetising when fully ripe. On the other hand, the tree has a gnarly character. I’m not sure whether to keep it.
Stand back and consider how much you love this tree. It’s old and will be supporting wildlife, and its gna