You need to find the Hackbard/Wergin church marriage record in La Salle Co, IL. Contact the following group and ask them if these records are available and what information the record provides:http://www.lscgg.org/
According to the Illinois marriage index on-line, they were married on April 27, 1877 in La Salle Co, IL. The "church" marriage record will hopefully indicate their parents names.
Then, go back and review the messages from Jim Baker and I from last September! I checked out the obituary and the town name is listed as Kolotz not Koltoz! Big difference. The town name was actually Kollatz - today known as Kolacz.
Jim noted Ferdinand's baptism at Nemrin. At the following website you will see that Nemrin was a town that belonged to the parish of Kollatz and thus, Ferdinand would have been baptized there:http://nemrin.kollatz.kreis-belgard.de/
Kollatz was in the county of Belgard in Pommerania - check out the following map for location:http://hinterpommern.de/Karten/Belgard/gemeinden.html
Then Jim pointed you towards the immigration record of the Wergin family. I checked the passenger records and they are noted as coming from Zitzmark. Actually, the town's names was Zitzmar and here are the details which note that the people in this town attended church at Zirkwitz.http://zitzmar.kreis-greifenberg.de/
Fortunately, these records survive and are available online through the LDS church on familysearch.org In fact, I was able to find the marriage of August Friedrich Gotthilf Wergin and Johanne Wilhelmine Charlotte Bartelt in 1857:https://familysearch.org/pal:/MM9.3.1/TH-1-18355-6881-44?cc=...
So, to sum up, you have had luck in finding them (or at least Jim Baker did) but you appear reluctant to accept the info - I am not sure why.
Perhaps, you will go back and review his messages (and mine). I would encourage you to inquire of Jim where he located the info on Ferdinand as I was not able to locate that information myself. Presumably, he has access to the Kollatz church records.
Best of luck in your continued research. There are lots of records to dig through and answers to be found now that you know where to dig.