I think you are right! I don't think there is a connection here.
My mother-in-law is a Duccini. Elizabeth Duccini (maiden name) she was born at Lyon, France. She is from Italian parents. Her brother was Gaetano Duccini also born in France. Quite a well know sculptor here in the "Bay Area" San Francisco and the rest of California. I never heard them mention of any family from Dubuque, Iowa. Like I said in my last post it is always worth a try. You never know who you might turn up!Right?