Using a stiff brush, thoroughly scrub the ham. Place in a large pot; cover with water and soak for 12-24 hours, changing water several times. Drain.
Cover ham with fresh water and bring to a boil; reduce heat and simmer for 20-25 minutes per pound. Ham is done when flat (pelvic) bone moves easily.
Lift ham from simmering liquid and remove to drain over sink. When ham is cool enough to handle, place on a large shallow roasting pan, jelly roll pan or cookie sheet. Remove the rind with a sharp knife, leaving 1/4-inch-thick layer of fat. Score the ham at 1-inch intervals. Spread with peach preserves and dot with pecan halves.
Bake in a 400 degrees F. oven for about 20 minutes or until the glaze browns.
Transfer ham to a serving platter and cool slightly. To serve, cut ham into paper-thin slices.