Remove giblets and neck from turkey, and chill for later use. Rinse turkey with cold water; pat dry.
Combine 1 teaspoon each of mixed-up salt, garlic powder, poultry seasoning, sage, and pepper; sprinkle cavity and outside of turkey evenly with mixture.
Place turkey, breast side up, in a large roasting pan, tucking wingtips under. Pour 2 cans chicken broth into roasting pan; drizzle melted butter over turkey.
Bake, uncovered, at 450° for 1 hour. Reduce heat to 425°, and shield with aluminum foil to prevent excessive browning. Bake 3 1/2 to 4 hours or until a meat thermometer inserted into thigh registers 180°, basting every 45 minutes with pan drippings.
Bring remaining 3 cans broth, neck, giblets, carrots, and next 3 ingredients to a boil in a saucepan. Cover, reduce heat, and simmer 45 minutes or until vegetables are tender.
Remove turkey to a serving platter, reserving drippings in roasting pan. Skim excess fat from drippings in pan, if desired.
Pour giblet mixture through a wire-mesh strainer into drippings in roasting pan, discarding solids. Bring to a boil in roasting pan over medium-high heat, stirring to loosen browned bits on bottom of pan.
Stir together flour and 1/2 cup water until smooth; add to giblet mixture, and cook over medium-high heat, stirring constantly, 10 minutes or until thickened. Stir in remaining 1/2 teaspoon each of mixed-up salt, garlic powder, and poultry seasoning. Serve with turkey. Garnish, if desired.
Note: For testing purposes only, we used Jane's Krazy Original Mixed-Up Salt.