It's actually "Leoina" not "Leonia". And the 66 used to be what most of my friends played with because we were young and our parents didn't want to pay for restringing all the time!
Another popular string was Toalson Gold ("Toa Gold"). But again, only the 15 gauge lasted long enough to play with more than a few matches.
Lois: "Peter, I'm not wearing any panties."
Peter: "That's ok, honey. We can throw that chair out."