Wow! Where do you find these databases??
If the family legend is true, then I believe that Maria Feiller/Feiler would have been born in Vienna. Also, the family states that the Kreineckers are "German" as opposed to "Austrian", so presumably Lorenz's mother came from a different part of the Empire (Bohemia?). In any event, the Viennese residency records might be a good place to start. At the risk of showing my ignorance, where can I find them? I've been searching a number of Austrian websites, but, as I don't read German, I'm not sure if I've seen these...
Thanks so much for your help!!