Drain and flake salmon. Remove backbone and discard. Place 1 cup croutons in 2 litre microwave-safe casserole. Sprinkle 1 cup salmon and 1 cup cheese over croutons. Repeat layers of croutons and salmon. Beat eggs, and blend in milk. Worcestershire sauce, dry mustard and salt. Pour over salmon mixture. Refrigerate, covered overnight or several hours. Remove cover and microwave on high 8 10 minutes, or until just set. Sprinkle remaining cheese and paprika over top. Microwave at 70 percent 2 4 minutes, or until cheese is melted and starts to brown. Allow to stand 5 minutes.