In a large saucepan, heat half-and-half to 175°; stir in the sugar and salt until dissolved. Whisk a small amount of hot cream into eggs. Return all to the pan, whisking constantly. Cook and stir over low heat until mixture reaches at least 160° and coats the back of a metal spoon.
Remove from the heat. Cool quickly by placing pan in a bowl of ice water; stir for 2 minutes. Stir in whipping cream and vanilla. Transfer to a bowl. Press plastic wrap onto surface of custard. Refrigerate for several hours or overnight.
Remove lids from jars of fudge topping. Microwave on high for 30-45 seconds or until warmed; whisk into cream mixture.
Fill cylinder of ice cream freezer two-thirds full; freeze according to manufacturer’s directions. Refrigerate remaining mixture until ready to freeze; stir before transferring to ice cream cylinder. Transfer ice cream to a freezer container; freeze for 2-4 hours before serving.