Bacon Cheesy Potatoes

Ingredients

• white baking potatoes (enough for 3 layers), scrubbed and thinly sliced (do not peel)
• salt and pepper to taste
• 1 medium onion, chopped
• 5 to 6 slices bacon, cooked and crumbled
• 1 lb. Velveeta cheese
• 1 c. Cheddar cheese, shredded
• 1/4 to 1/3 c. milk
• 1 stick margarine, melted
• paprika