I finished my online research for Frank Labecki and found 2 additional pieces of documentation I thought you'd like to look at - both are on Ancestry.
In the "Wisconsin, Births and Christenings Index", there is a listing for Sopie Labenski/Sophie Zabzki. This is a daughter of Frank's & Josephine's born in Milwaukee in 1880. In addition, I found the entry for the family in the 1880 US Census under the name Frank Labinzki. This shows 2 earlier children as well as Sophie - and indicates the couple were married at least 5 years earlier than commonly thought.