Q.Why does my peach tree have fruit forming, but no leaves
The tree is at least 27 years old, probably more, as it was already in site when we bought the property. We were told it was an almond, so my guess is it had never fruited. Anyway, after a couple of years it produced 250 wonderful peaches. It has continued to fruit reasonably well over the last 25 years, but this year, it has fruit forming and very few leaves. Several branches are clearly dead. Is the tree now finished its useful life, or is it diseased?

Certified GKH Gardening Expert
It could be a little of both. It is rather old for a peach tree, and just like people and animals, when plants get older, they become more susceptible to pests and diseases.
It sounds like it might have a fungus, so you can try to treat it with a fungicide, but don't be surprised if the tree does not pull through. It has had a good a productive life.