I think I have researched dozens of websites, blogs, and forums on limoncello making, but I come back to this one as among the best. Aren't the Italians the inventors, and thus the experts? I first tried limoncello in Italy about six years ago, and so M Marlow's recipe sounds most authentic.
Interesting how many opinions there are about vodka vs grain alcohol, but the proof is in the tasting, and after reading, and then tasting Everclear-based 'cello, I would not even think of using vodka. Why simulate when you can make the real thing? But, to each his/her own. My pal made his own first-rate limoncello, but Villa Massa is good and is easily purchased. Thus, it's time to explore the other citrus candidates! I'll follow the lead of others who have commented here. Thanks to all who have shared... this is intriguing!
Bill In Bay