Singer 503 Slant-O-Matic Sewing Machine Instruction Manual (Model 503 Slant-O-Matic) - 100 Pages. Lost your sewing machine's manual? We've got you covered! This instruction manual is the ultimate guide to unlock the full potential of your Singer 503 Slant-O-Matic. No more confusion or frustration—just clear, concise instructions right at your fingertips. What's inside? Everything you need to know from setting up to mastering your sewing machine and all its features.