Preheat oven, prep pan, and cook macaroni:
Preheat oven to 375°F. Generously butter a 9-by-13-inch glass baking dish; set aside. Bring a large pot of water to a boil; add salt and macaroni. Cook until al dente according to package directions. 

 Drain macaroni and toss with butter:
Drain, and return to pot. Add butter, and toss until pasta is coated and butter has melted; set aside. 

 Combine milks, eggs, and seasonings:
In a medium bowl, whisk together evaporated milk, skim milk, and eggs. Add seasoned salt, garlic powder, 1 teaspoon salt, and 1/2 teaspoon pepper; set aside. 

 Arrange macaroni and cheeses in dish:
Place 1/3 macaroni in an even layer in the bottom of prepared baking dish; cover evenly with 1/3 cheese. Repeat with remaining macaroni and cheese mixture. 

 Add milk mixture:
Pour milk mixture evenly over contents of baking dish. Sprinkle with paprika. 

 Bake:
Bake until top layer is lightly browned, 35 to 45 minutes. Let stand 10 to 15 minutes before serving.