Schwaigern is a tiny little town. You can walk across it, north to south, in 5 minutes flat. There's 1 church dating back to the time of the Kepplingers. I believe it's protestant. Records show that more than 50% of the population died from the black death at one point. So populations were likely very tiny even at that point in its history as compared to today.
According to the church folks, the Kepplingers didn't appear to have originated from Schwaigern. The father had a contact in Salzburg, Austria that was mentioned. I think that we'll likely find the previous generation hailing from Austria.