In a 4 qt Dutch oven cook the Water, Celery, Shallots, Old Bay and the Shrimp over Medium High. When the Shrimp shells have turned pink and the Shrimp is opaque use a pair of tongs to remove the to a sheet pan to cool.
In a medium sized bowl whisk together the Evaporated Milk, Milk, Flour, Anchovies, Lemon Juice, Salt, Pepper and Crushed Red Pepper. Stir this mixture into the broth and lower the heat to Medium. Cook for 10 minutes.
While the soup continues to cook peel the Shrimp. Set aside 16 of the Shrimp and give the remaining Shrimp a rough chop. Place the chopped Shrimp back into the Pot and continue cooking for another 2 minutes.
Ladle the soup into bowls topping each of the bowls with 4 of the reserved ShrimpServe with a side of toasted Sourdough bread.
If you want to make it more like a "Chowder" add medium-sized potato that has been skinned and cut up into a small dice along with half a Red Bell Pepper that has also been cut up into a small dice. Add that to Celery and Shallots.