Place the squid in a large bowl of cold water and let soak for at least 20 minutes.
While the squid are soaking, shell and devein the shrimp, wash them in cold water, and place them in a colander to drain.
Pull off the tentacles from each squid with one hand, holding the sac with the other. The tentacles come away with the inside pulp of the squid to which they are attached. Cut the tentacles straight across just above the eyes. Discard all the pulpy matter from the eyes down. Squeeze off the tiny beak at the base of the tentacles. Wash the tentacles in several changes of cold water, drain well, and pat dry with paper towels. Set aside.
Remove the floppy, cellophanelike bone from the sac. Peel off the sac’s outer mottled skin. Cut a tiny—no more than ¼ inch—opening at the bottom of the sac. Hold the sac under running water with the large opening facing the faucet and wash it thoroughly. Drain and pat dry.
Put the shrimp in a bowl and toss with half the olive oil. Add the garlic, parsley, bread crumbs, salt, and several grindings of pepper and toss repeatedly to coat the shrimp well.
Stuff the squid sacs no more than three-quarters full with the shrimp. Sew up the large opening with needle and thread. When all the sacs have been stuffed and sewn, put the needle away safely.
Choose a sauté pan that can subsequently accommodate all the squid without overlapping. Put in the remaining olive oil and turn on the heat to medium high. As soon as the oil begins to be hot, slip in the squid sacs and all the tentacles. Let the sacs brown on one side, then turn them until they have browned all over.
Add the wine, let it bubble for a few moments, then turn the heat down to very low and cover the pan. Cook for at least 1 hour, turning the squid from time to time.
To serve, first slice off a thin strip from the sewn top to dispose of the thread, then cut the sac into 3 rounds. Place the rounds in the center of a platter, pour all the pan juices over them, and surround them with the tentacles. Serve at once.