1. In heavy 2-quart saucepan, with wire whisk or fork, beat milk, eggs, salt, and 3/4 cup sugar until blended. Cook over medium-low heat, stirring frequently, until mixture thickens and coats a spoon, about 30 minutes (do not boil or mixture will curdle). Remove saucepan from heat; stir in orange extract. Pour custard mixture into medium-sized bowl; cover and freeze about 3 hours or until almost firm.
2. With back of spoon, spread frozen mixture evenly to line inside of 8 1/2" by 4 1/2" loaf pan. Cover loaf pan; freeze until firm, about 1 hour.
3. Grate 1 teaspoon peel from half of lime; set aside. Wrap remaining lime half with plastic wrap; refrigerate to use for garnish.
4. In small bowl, with mixer at medium speed, beat heavy cream and 1/4 cup sugar until soft peaks form. Fold in candied fruit and grated lime peel. Remove pan from freezer; spoon whipped-cream mixture into center of frozen custard; cover and freeze until firm, at least 6 hours or overnight.