Heat oil in a medium sauce pan over medium heat until shimmering. Add the shrimp shells, celery, and onions, and saute until the brown spots appear on the shrimp shells.

Add water, thyme, and bay leaves, and bring to a boil. Reduce heat to maintain a simmer, and cook for 30 minutes.

Towards the end of the stock's cooking time, place the bacon pieces in a cold 4 quart Dutch oven or saute pan (you'll need a lid or foil to cover), and turn on heat to medium. Cook until the bacon is crisp and the fat has rendered. Remove the bacon to a paper towel-lined plate, and set aside.

Add the onions, celery, and peppers to the pot, and saute until the onions are soft and starting to go translucent, about 8 minutes. Add the garlic and stir well. Pour in the wine, if using, and simmer until evaporated/incorporated into the rice (just a few minutes). Add the tomatoes and parsley and mix into the rice.

Strain the shrimp stock through a fine mesh sieve, pressing down on the solids with a spatula to extract every last drop (discard the solids). You should have about 3 cups of stock (if less, top off with plain water).

Add the stock to the rice mixture and bring to a boil, then reduce heat to maintain a zippy simmer. Cover the pot and cook the rice for 15 minutes, or until the liquid has been absorbed.

Add the shrimp on top, spread out in a single layer (if possible). Cover, and cook for 5 minutes more, or until the shrimp is opaque with pink edges and plump. Add the reserved bacon, and gently fold the shrimp into the rice, taking care to "fluff" rather than "stir," which might make the rice gummy.

Season with a pinch of salt and freshly ground black pepper, top with a sprinkle of chopped parsley, and serve.