I was looking up some stuff and found a bit of interesting information I'd like to pass on to you: First, I found your Henry Frederick listed in the 1900 census california, monterrey county, gonzales township with his family, including your kenneth. he is listed as "fred h." which has been a problem all along with him and previous research. for some reason he went by frederick henry for awhile. If you would like me to email the census page to you, please send me you email address via private email and I will be happy to do that for you.
second, in looking back at some of my old files, I found a newspaper article about soem of my Melville girls visiting their cousins "the Misses Chaboya" in 1900 SALINAS. Strangecoincidence that my John and your Henry are both connected with Salinas. Henry's mines were in Salinas.
there are several more coincidences with these two families that lead me to believe they are connected somehow.
have you, by any chance, discovered the names of Henry's parents? I am sure that there is a record of his marriage to Mary Pugh. If you can find that, the names will be listed on the certificate. I got the information I have about my John from the Book of Marriages 1855-1930 for Our Lady Help of Christians Church (aka Valley Church and Pajaro Church) even though they were puportedly married at the Mission of Santa Cruz. I would really be interested to know Henry's parents.