Off heat, whisk eggs, yolks, sugar, and salt in heavy 3 or 4 quart saucepan. Stir in milk, one half cup at a time, blending well after each addition.

Heat slowly over lowest possible flame, stirring constantly, until custard registers 160 degrees on instant thermometer, thickens, and coats the back of a spoon, 25 to 30 minutes. Pour custard through sieve into a large bowl; stir in liquor, vanilla, and grated nutmeg .

Cover with plastic wrap and refrigerate until well chilled, at least three hours and up to three days.Just before serving, whip cream in medium bowl, to very soft peaks and gently fold into custard mixture until incorporated. Serve in chilled punch bowl or cups.