Clean the moscardini and squid (remove the cuttlebone, cut out the eyes and the beak in the centre of the tentacles, then rinse clean). Scrub the mussel shells well and remove the “beard” (holding it with your fingers and pulling it towards you from the broader part of the mussel) and then wash them thoroughly, together with the clams. Put them in a saucepan over a low heat until they open, stirring from time to time, and then turn the heat off. Allow them to cool a little and then remove the majority from their shells, setting aside a few of each kind with their shells on (10-15 clams, 10 mussels) to use as a garnish. Strain the molluscs’ cooking juices carefully through kitchen paper or a fine cloth and set it aside for later, when at least half a glass (depending on the consistency of the sauce) will be needed to add to the mussels and clams. Bring some water to the boil, drop the moscardini into it and cook for 10-15 minutes. Put the oil into a large, heavy-bottomed frying pan and sauté the cloves of garlic and the chopped shallot until they begin to turn golden; add the boiled moscardini and the squid, which you have previously cut into pieces. Cook over a low heat for 15 minutes and add ½ a glass of white wine. When it has evaporated, add the prawn tails and king prawns; after 5 minutes cooking, pour in the rest of the wine and add a pinch of salt, while keeping the pan covered. After another 4 or 5 minutes add the mussels and clams, pour in ½ a glass of their cooking juices and leave to cook for 10 minutes. Break the eggs and beat them in a bowl with a pinch of salt and pepper, then add the Parmigiano (this will make the egg more creamy, but if you don’t like it you can always leave it out). Cook the linguine until “al dente” and tip them into the pan with the seafood. If there's some left, add a little of the molluscs’ cooking juices, or if not add some of the water the pasta was cooked in. Mix everything together, remove the pan from the heat and pour in the beaten eggs, stirring quickly to amalgamate it well. The egg mustn't "scamble", it should remain creamy: it’s essential to mix it with the pasta rapidly! Before serving add the mussels and clams in their shells that you set aside earlier, the chopped parsley and a sprinkling of freshly ground pepper.