I find an obit for Lois Schinkel, 89, in 1998. She was wife to Lloyd Schinkel, daughter of Axel and Tina (Wilberts) Swenson.
I assume this is the correct woman. Do you have / want her obituary?
I find an obit dated 1966 for an Anton Prestwick; he married Tena Swenson in 1944.
Tena's obit ran in the Aberdeen paper on October 7, 1965. I can type it up for you if you would like.