A fishmonger can shuck the clams for you; or, if you have a clam knife, you can do the job yourself.
Place clams in 1 layer on a baking dish, and refrigerate. Preheat oven to 400 degrees, and place rack in middle position. Place bread on a baking sheet, drizzle with oil, and sprinkle with salt. Bake until toasted, about 5 minutes. Remove, and let cool. Turn oven to broil.
Place butter in a small bowl, and mix until very smooth. Stir in shallots, garlic, oregano, parsley, and 1/8 teaspoon pepper until incorporated. Spoon 1 teaspoon butter mixture on top of each clam, spreading to cover, and top with a few pieces of bacon.
Broil until clams are cooked and bacon is crisp, about 6 minutes. Transfer 1 clam and some juice to each toast. Broil 1 minute more; serve immediately.