The Mystery of Randolph Shewan

Over the years I have inherited a lot of old photos. In some cases I know who is in them and in some cases I do not. And then there are those where the people are identified and I still don't know how they connect to the family. Randolph Shewan falls into the latter category. I have a copy of an 1880 photograph of this handsome fellow, but who is he? His age is about right to be a younger brother or cousin of Mary Elizabeth Shewan, the first wife of my grandfather's first cousin James A. Buchanan. And the photo was passed down through the descendants of Mary Elizabeth Shewan, which indicates that there is a connection.

At familysearch.org I find him in multiple US census records as an adult. But who were his parents?

I did some more searching for Randolph Shewan, born 1861 in Utah.

This 1870 census record includes a Shewan family that seems to fit our Shewans.
Note: M.E. Shewan who is born in Pennsylvania in 1856 is probably Mary Elizabeth, who is already known to be born in that time and place, and a J.R. Shewan is shown as born in Utah in 1861, which matches Randolph's known year and place of birth.
Wm Shewan M 45y England
M E Shewan F 41y England
Eliza Shewan F 16y England
M E Shewan F 14y Pennsylvania
J R Shewan M 9y Utah
W H Shewan M 6y Utah
Annie Shewan F 2y Nevada
https://familysearch.org/pal:/MM9.1.1/MZMW-D7P

And Randolph's death certificate gives his father's name as William W Shewan, which matches the 1870 census:
name: Randolph Shewan
death date: 09 Apr 1934
death place: Seattle, King, Washington
gender: Male
race (displayed on form):
age at death: 71 years 8 months 22 days
estimated birth year: 1863
birth date:  [It calculates to 18 Jul 1862.]
birth place:
marital status: Married
spouse's name: Mary Shewan
father's name: William W. Shewan
father's birth place:
mother's name: Unknown
https://familysearch.org/pal:/MM9.1.1/N352-QSH

I also found the death of John R. Shewan, which lists his parents as John R. Shewan and Parthenia Smith.
I found the marriage record for Randolph Shewan and Porthena Smith in 1883. California, County Marriages   https://familysearch.org/pal:/MM9.1.1/XLHY-8LF

Randolph was a widower when he married Mary Shumacher Shill on 20 Jan 1910 in Vancouver, British Columbia, Canada. https://familysearch.org/pal:/MM9.1.1/JDD3-TQ6 
At that time he identified his father as William Shewan and his mother as Mary Taylor.

I think this proves, beyond a reasonable doubt, that Randolph Shewan (the handsome fellow in the 130 year-old handed-down family photo) is in fact a younger brother of Mary Elizabeth Shewan who married James A. Buchanan. His full name was apparently John Randoph Shewan, which matches the J R Shewan in the 1870 census, which also lists siblings I was unaware of.