Melt 2 tablespoons butter in a skillet over medium heat. Add bell peppers, and sauté 3 minutes or until tender.
Place peppers, crabmeat, shrimp, and scallops in a bowl; toss gently. Add mayonnaise, mustard, seafood seasoning, 1/2 teaspoon black pepper, juice of 1 lemon, and parsley; stir gently.
Spread seafood mixture evenly on fillets, and roll up. Arrange, seam side down, in a 13- x 9-inch baking dish. Melt remaining 2 tablespoons butter, and brush tops of rolled fillets. Season lightly with salt and remaining 1/4 teaspoon pepper. Squeeze remaining lemon over fillets. Pour wine into baking dish. Cover dish with aluminum foil; make several slits in foil to allow steam to escape.
Bake at 375º for 30 to 35 minutes or until fish flakes with a fork. Remove fillets with a slotted spoon to a platter. Serve with Simple Lemon Butter.