http://www.cowboyshowcase.com/saddle_makers.htm
http://www.cabincreekcds.com/N.Porter.htm
N. Porter Saddle and Harness Company
Arizona, The Youngest State, 1913
The business conducted under the name of the N. Porter
Saddle and Harness Company was established in 1897 by N.
Porter who came to Arizona from Abilene Texas. He had
served in the war as a Confederate soldier and was always
allied with southern interests. In 1897 he removed from
Texas to Arizona and continuing in the line of business in
which he had formerly engaged, opened a harness and saddlery
establishment in Phoenix. From the beginning the new
enterprise prospered and in a comparatively short space
of time a good trade had been secured, while with passing
years the business has rapidly increased. In June 1906 the
death of N. Porter occurred since which time his sons, E.H.,
F.S. and J.R. Porter have succeeded to the business, which
they are now carrying on. It is the largest store in its
line in Arizona. They carry their own makes of harness
and saddlery and enjoy an extensive patronage, for anything
needed in this line can be found in their establishment
while their business are at all times reliable. Their
store has a frontage of twenty five feet and a depth of
one hundred and thirty seven feet. From eight to twelve
men are employed and their manufactured products are
notable for their durability and their excellence of
finish. Their trade has grown with the settlement of
this section of the country and the brothers are
maintaining the high standards established by their
father.
http://www.cowboysindians.com/forums/showflat.php?Cat=&Number=849&Main=845
this is a N Porter Saddle for sale, it doesn't say what "make" it is, but might not hurt to check it out.
Hope this helps, gives his sons initials so you might do a search on them as well.