New England Fish and Shrimp Chowder

I'm cobbling this recipe together from a couple different recipes. This is a work in progress.

Ingredients

Chowder:
4 slices thick-cut bacon (about 4 ounces), cut into ¼-inch pieces
1 large Spanish onion, diced medium (about 2 cups)
2 tablespoons unbleached all-purpose flour
2 (8-ounce) bottles clam juice
4 cups shrimp stock (see recipe below)
1 lb fish fillets such as cod
1 lb shrimp
3 medium boiling potatoes (about 1 ½ pounds), scrubbed and diced medium
1 large bay leaf
1 teaspoon fresh thyme or¼ teaspoon dried thyme
Butter / flour roux
1 cup heavy cream
2 tablespoons minced fresh parsley leaves
Shrimp Stock
Shrimp shells from 1 lb shrimp
4 cups water

Instructions

Shrimp Stock
Bring shrimp shells and 4 cups water to a boil. Reduce heat to medium-low and simmer for about 20 minutes. Strain out shrimp shells. (Note to self: this is copied from my gumbo recipe which uses 5-1/3 cups water for shrimp shells from 1 lb of shrimp).

Chowder
Fry bacon in kettle over medium-low heat until fat renders and bacon crisps, 5 to 7 minutes. Add onion to bacon; sauté until softened, about 5 minutes. Add flour; stir until lightly colored, about 1 minute. Gradually whisk in bottled clam juice and shrimp stock. Bring to simmer, gently lay fish fillet in liquid, cover, and let fish stand until opaque and nearly cooked through, about 5 minutes. Transfer fish to bowl. Return pot to medium high heat. Add potatoes, bay leaf, and thyme; simmer until potatoes are almost tender, about 10 minutes. Make a roux of melted butter cooked with equal amounts flour; add to pot to achieve desired thickness. Add shrimp and simmer for another 5 minutes. Add cream, parsley, salt (if necessary) and ground pepper to taste; bring to simmer. Return fish to pot, cover, remove from heat, and let stand for 5 minutes. Stir gently to break fish into large pieces. Season and serve.