WOW, I think I've got him. Must make a correction: the place is Weitersroda, today Hildburghausen-Weitersroda. Both acts of emigration in 1854 and 1862 were officially registered. Johann Klett was a pub owner and in 1862 emigrated a second time with a wife and six children.http://www.thueringen.de/imperia/md/content/staatsarchive/me
YOu will find him in the middle of that database.
The duchy mentioned was Sachsen-Meiningen.
Lucky you. I guess those people are family members:https://familysearch.org/search/tree/results#count=20&qu
Now you know where to start. I could recommend a professional local genealogist if you need one.
I'm so happy I could help you.