Hi Cathy: Eric Snyder in Ottawa here.I think the place that Gustav Kull came from in Ukraine was "Luck"... now part of Poland.
I don't know this for sure, but I believe brother and sister, Gustav Kull and Emma Kull, married a brother and sister, Julius Janke and Emma Janke.All the marriages took place in Winnipeg, Manitoba.
Julius Janke was a builder who built quite a lot of residential houses in the Elmwood area of Winnipeg, Manitoba, Canada.
For a short time, after his wife Emma died in 1950, Gustav Kull lived with his sister and brother-in-law, the Jankes, on Castle Avenue at the corner of Grey Street in Winnipeg.
Leontina Kull-Kauk (age 91) and Rosalie Kull-Snyder (age 88), children of Gustav, are both still alive and living on Castle Avenue in Winnipeg. They would be able to provide details on the Janke descendants (and maybe ancestors...).
Look forward to hearing from you if you get any more details!