In a food processor, grate or process 3/4 pound day-old bread (crusts removed) to make fresh breadcrumbs.
In a bowl, combine the breadcrumbs, 2 cloves minced garlic, 1 cup softened butter and 1 tablespoon white wine; knead like bread dough until smooth.
Roll into a 3-inch diameter log; wrap in plastic wrap. Refrigerate at least 1 hour until hardened.
Preheat oven to 450 F.
Divide 30 cooked large shrimp among 6 scallop shells or ovenproof ramekins; sprinkle with 1 tablespoon sherry. Top with 1/4-inch slices of the bread log. Sprinkle with 1/2 teaspoon paprika.
Bake for 4 minutes. Lightly separate bread crumbs with a fork to cover shrimp more evenly. Sprinkle with more paprika, if you like. Bake until bubbling and golden brown, about 4 minutes longer.