1. Combine 3/4 cup sugar, egg yolks, and whole egg in a medium bowl. Scrape seeds from vanilla bean, and add seeds, pod, and half-and-half to saucepan. Warm over medium-high heat 8 minutes or until mixture begins to steam. Do not boil. Slowly whisk into egg mixture. Return to saucepan, and cook over medium heat, stirring constantly, 10 minutes or until mixture coats back of a spoon. Whisk in butter and cream. Let cool, and chill 8 hours.
2. Toss peaches with remaining 1/2 cup sugar and salt; let stand at least 30 minutes in a glass or stainless bowl.
3. Puree peaches and peach preserves in a blender until well combined but not completely smooth. Combine peach and custard mixtures, and freeze in an ice-cream maker according to manufacturer's instructions.