All those who played the game were correct. I believe it is indeed a quince. I poached it from a heavily laden tree in the park, now what to do with it? Alice, in Chez Panisse Fruit, a book I just happen to have from the library, says:
“The decline of the quince may be explained by the fact that it is not a convenience food. The yellowish-white flesh of raw quince is inediblely hard, dry, and astringent and must be cooked before it becomes soft and flavorful and turns a lovely pink color. The few steps in preparation are quick and easy, but the cooking takes a long time.”
The one I picked was fuzzy and it seems that the less fuzz, the more ripe it is. She says that it will keep for a week or two on the counter or longer in the refrigerator. When I have time, I will perhaps try a very small quince and apple tart. It looks like they have to be poached before being turned into a tart. Stay tuned.