To prepare sauce, melt butter in a saucepan over medium heat; stir in flour, salt, paprika, and pepper. Cook the mixture 30 seconds, stirring constantly. Gradually add milk, stirring with a whisk. Cook 3 minutes or until thick, stirring constantly. Remove from heat. Add cheddar, Worcestershire, and mustard; stir with a whisk until smooth. Keep warm.
Arrange toast on a large baking sheet. Arrange turkey evenly over toast. Drizzle sauce evenly over turkey; top each toast slice with 1 tomato slice. Sprinkle evenly with bacon and Parmesan. Broil for 7 minutes or until thoroughly heated and lightly browned. Serve immediately.