I would be most interested in seeing a copy of your picture.
My grandfather, Heinrich "Harry" Bock, had several sisters, two of which were named Viola and Lora. The date, the location (less than 20 miles from their home) and especially finding both names together lead me to suppose they two of the folks pictured on your post card. Lora and Viola were daughters of Gustav A. Bock and Emma Weisshof Bock of Dale Township, Outagamie Co., Wisconsin. I'm afraid I do not at this point recognize any of the other names you listed.
In the early 1900's Grandpa Harry was an amateur photographer who, in the custom of the day, often printed his photos on post card stock. We have many of his cards as well as several of the original glass plates from which they were made. (Bocks apparently threw out nothing. Bassed on my difficulties in this area, I believe this to be a genetic trait.) It is quite possible that Harry shot the photo and that we may have the original plate!