My father's limoncello recipe (and picture of his product)

I'm going to paste below my father's verbatim limoncello recipe, which he e-mailed to me a few months ago. Enjoy!

vodka.  buy a bottle, have a good stiff drink to make a little room in bottle.  put in zest of 6-8 lemons.   let rest in dark pantry from 1-2 weeks.  turn bottle over every few days to submerse rinds.  whenever you think it is ready mix with simple syrup about ratio of 1:1. just do to taste..  

Simple syrup is 1 cup water to 1 cup sugar.  Boil water, add sugar, dissolve, cool..

enjoy, but save a little for me!