Whisk together the egg yolks, sugar, salt, citrus zests and orange juice. Set aside.Heat the heavy cream and milk in a medium sauce pan over medium heat. Add the scraped vanilla seeds as well as the remaining vanilla pod. Heat until almost simmering. While whisking the egg yolk/ juice mixture, slowly drizzle in about a third of the hot milk mixture, then pour the tempered egg yolks into the pot and heat to 165 degrees. Strain the custard through a fine mesh strainer into a bowl and cover with plastic, laying the plastic directly on top of the custard. Chill for at least 4 hours, though overnight is best.Pour the chilled custard into an ice cream maker and churn for about 15 minutes. Scoop the ice cream into a container and place it in the freezer to harden.