I had tried to contact Robert in 2007 and never got a response. I was interested in more info and the photo as well. I have some research about Showalter concerning his time with the 4th Arizona Brigade in late 1863 and early 1864... mainly what I've been able to piece together from the service records of people who served under him and Col. Baird.
Are you looking more into his activities before leaving California or anything you can find. I also have a copy of a letter he wrote trying to get Confederate support to take an expedition to Arizona to look for gold and such.