On this page from the year 1455 we can see payments which were given to all workers on the Seeberger farm. It is a bit confusing, that the names Seberger, Seberch and Seberg are on this list not only once but several times.

1456. As you can see on this page, you can find another way of writing the name as Selberger!
 

In 1457 it becomes very interesting! For that year only a blank page with the name Seberger on top was found. That proves my theory that Jacob died very early and his wife took over for some months. I guess that the townclerc prepared the pages at the beginning of the year and logically for the Seeberger farm too. He couldnt know at that time that no payment came from this family in this year.