ISO: How did Lamingtons make their way to Cleveland and nowhere else??

My mother's family was from Cleveland. I still remember my grandmother making Coconut Bars. I used to have her mail me "ground coconut" so I could make them here in NY. Thirty-plus years later, in the city that has everything, it is still near impossible to find ground cocount, let alone coconut bars. (We never used shredded.) But, alas they exist in -- of all places, Australia -- as lamingtons! How did they get to Cleveland and why to almost nowhere else?? Anyone know? In the meantime, whenever I make them here, people flip over them. Still so unique, all these years later. I was surprised to see -- in the Hough recipe -- that they are served at room temp. I always thought they were to be served right out of the freezer. That's what Grandma Sylvia did. Cold, wet, chocolatey and yummy!!