Set aside 1 cup of chopped cucumber for a garnish. Soak the bread in water until soft, about 2 minutes. Place soaked bread, the rest of the cucumber, garlic, 3 of the scallions, vinegar, lemon juice, 1/4 cup of the almonds, salt and 3 tablespoons of olive oil in the bowl of a food processor and process until cucumbers are completely blended and liquid and almonds are almost completely invisible, about 1 to 2 minutes. Season with additional salt and vinegar, if desired.
To serve, ladle 1 cup gazpacho into a bowl. Mound 1/4 cup reserved chopped cucumber, 1 tablespoon scallions, 2 tablespoons grapes and 1 teaspoon almonds in the center of the soup.