Wow, I assumed that the 2nd photo was from the war only because it was taken in Saarbrücken. Don't know of any family from the Prussian area. There is also a Schaeffer(grandfather) side of the family but I have no info other that they came from Stuggart area, which as far as I know is in Wurttemburg.
Wilhelm was born in 1844, the 2nd of eight children from 2 mothers and a father named Heinrich. Most of his brothers left for the US before in the years preceding the war. After the war Wilhelm married in '75 and started having kids. As the rumor goes he emigrated to the states in '83 as he did not want his sons to have to fight for the Kaiser. As far as I now when he left Germany he took the last of his siblings and his stepmother with him. However there is family still in the general Odernheim area and my grandmother was in correspondence with them up until her death in the early 1970's.
I assumed that Odernheim was in Bavaria. On the US census Wilhelm put down Odernheim, Bavaria as his origin. Any idea why someone not from Bavaria would serve in a Bavarian unit?
As for the painted photo, I found an old Osprey book on the German Empire which mentioned the weapons the Bavarian Chev. used during the FP war and looked pretty close. But I guess that all cavalry units would use a similar kit during that period.
Thanks for all the great info.