I checked the marriage index that covers 1848 - 1874 and I don't find any Thompson that married to a Peterson.

Your Ole Pederson & Thona "Kittsdtr' Pederson are both buried in Grace Lutheran Church Cemetery. Tone died in 1904. It looks like Klokkenvenger might be the farm name?

Check www.jansdigs.com and go to the Winnebago County link and then to the cemetery link then to the Grace Lutheran link. There might be a record of the marriage at the church but one was not filed at the courthouse. Of course keep in mind that they could have married elsewhere.