after using all your info if I were you I would research a Ernest Martin Kaltenbach {various spellings}
I am just going to post this to show he did show up in Riverside eventually
this man lived in Imperial Calf. until the WWII draft reg which puts him in Riverside in '42

WWI
Sept 12 1918
Name: Ernest Martin Kaltenbach
Event Type: Draft Registration
Event Date: 1917-1918
Event Place: Imperial County, California, United States
Gender: Male med/med/blue/brn
Nationality: United States
Birth Date: 12 May 1876
Birthplace: , , United States
stage driver

WWII
Name: Ernest Martin Kaltenback
Event Type: Draft Registration
Event Date: 1942
Event Place: Banning, Riverside, California, United States
Gender: Male 5'8"/ 155lbs/ blue eyes/ ruddy complexion/grey hair
Birth Date: 12 May 1877
Affiliate ARC Identifier: 603155

I used familysearch.org

if nothing else perhaps you can find his descendants and see what happens

I am not related

I have no personal knowledge of anyone involved

Best Regards,

Connie