From Karen Oliver (who also happens to be a wonderful tomato breeder) -
“The story goes: an old man brought a big tomato as a present to a lady he was sweet on who worked with a friend of mine in a garden center about 12 years ago. He had apparently grown this variety here in the Edmonton area for many years and it was his pride. My friend thinks he might have called it "Chicago". He is nowhere to be found anymore. The lady shared the tomato with the staff at lunch, my friend saved some seeds and gave them to me to ferment. I have grown it often since, saved seed (and it always comes perfectly true).”
After discussion on our tomato forum it was decided to name it “Zena’s Gift” as the lady to whom the tomato was given was named Zena.