I didn't need to make a second trip to Schwaigern. I had a German friend speak to a lady (Mrs. Buggle) who is the church's liaison for geneological matters concerning the "kirche buch" (church book).
As it was explained to me, the Kepplinger's (spelling in the church book) there is NO DOCUMENTATION that they were born in Schwaigern. They merely lived there for a spell and their names and birthdates were recorded into the church book. In other words, they came, lived, registered in the church, and then left. The question is: where did they come from?
There is no mention at all of where they lived, what Leonhardt did for his occupation, or the wife's maiden name. There is no "date" to this information as well. Much of what we online regarding this Kepplinger family has been "assumed" by Caplinger/Kepplinger researchers.
Now on the other hand, if you look in the German "white pages" for Käpplinger in the state of "Baden-Württenberg" you'll find plenty of Käpplingers in this area. I would highly suggest that these folks be contacted as many Germans had to "prove" their ancestry during the war and so many have their geneologies back hundreds of years (but one has to wonder how accurately they were done as they were constructed under some duress). But a caveat: many people in this area do not read/write English and many speak the Swabian dialect, so then German doesn't even help either.
So in all, it doesn't look as though we can prove that any of our Kepplingers are born in Schwaigern. One clue is in Leonhardt's wife. (I see online referenced that she is an Umbenhauer, but where is the primary resource documentation to prove this is her last name?). If she truly is Swiss, then maybe we should look in that direction?
It's such a mystery. I just wish that people would cite primary, and not secondary, resources.
I do have a copy of the family's information from the church of Schwaigern for anyone interested. It's about as official as one can get without photographing the Kirche Buch itself.