I realized that I needed to check for Henry Benz, grandson of Jacob Hoffman, in the 1905 Wisconsin state census that is now available on the FamilySearch pilot site. Henry's great-grandson had told me the family moved to La Crosse in 1905, so it was interesting to see if he was on the census, the official date of which was 1 June 1905.
Sure enough, Henry Benz was enumerated in La Crosse with his second wife, Nettie, son Clarence, and a Byron Benz who is also listed as his son, but is not in fact his son. I think I got a rundown on some of the other Benz relatives, but don't remember who this one is. The birthplace of Henry's parents is given as Illinois though both Mary Hoffman and Ambrose Benz were born in Switzerland.
Here is the page with the Benz family down at number 183: