I am fairly new at the genealogy thing and have been at it a short time. I found your post today I see its rather old better late then never lol. I am not sure if you have found the answer yet but Placidus is my Greattttttttetc grandfather. As for a Mary Wallburga I havent gotten that far in the tree yet, skimming through what I have I see Marys and a walburga but the dates dont seem to match I am sure I havent dug deep enough yet. I am going to China twp.MI this weekend to talk with a man who has kept a lot of records regarding the family. If you already found your answer or a still looking let me know maybe I can help.