In a stainless steel bowl, beat eggs with the lime peel until fluffy. Remove lime peel and mix in the evaporated milk.

Place in a double boiler (or use a stainless steel bowl over a pot of simmering water) over medium-low heat, and stir constantly until the mixture has thickened. Turn off the heat.

Transfer the mixture to another bowl and add all other ingredients except the rum and bitters. Stir well and allow to cool completely.

Once completely cooled, add the bitters and rums. Pour mixture into sterilized glass bottles and refrigerate.

Serve well-shaken and over ice.