That is very nice of them to send the marriage record!
I know you have the following, but I have been looking around, and have not found any answers, so I thought I would try summing things up, in hope of finding a clue. Your findings are in [ ].
[James Whitney - July 25, 182? - May 3, 1903?, Chariton, Iowa
and his wife, February 3, 1823? - September 24, 1872?]
(The headstone is difficult to read)
1900 Chariton, Lucas Co, IowaLide Wren, Head, June 1853, age 46, Wd, mother of 2 children 1 still living, born England as were parents
Edith N(?), daughter, March 1889, age 11, born Iowa, parents born England
Carrie C Wren, niece, October 1888, age 11, born Pennsylvania, father-England, mother-Pennsylvania
James Whitney, father, July 1822, age 77, Wd, born Wales as were parents
1895, Iowa State Census - 2nd Ward, Chariton, Lucas Co.James Whitney, age 71, born Wales
1885 Iowa State Census (Correct James Whitney?)
James Whitney, age 58? or 38?, Farming, born England
David, age 36, Farming, born England
Eliza, age 32, born England
Alice, age 16, born Lucas County
Olie Spencer, age 16, born Lucas County
1880 Chariton, Lucas Co., IowaJames Whitney, age 53, Farmer, born Wales as were parents
Eliza, age 26, daughter, Keeping House, born England, father-Wales, mother-England
Mary E, daughter, age 19, born Illinois, father-Wales, mother-England
E. Alice, daughter, age 11, born Iowa, father-Wales, mother-England
1870 Liberty, Lucos Co., Iowa, Post Office Chariton
James Whitney, age 45, Farmer, born Wales
Mary, age 45, Keeping House, born England
Mary, age 9, born Illinois
Allace, age 2, born Iowa
[1860: Marriage to Miss Mary Lee]
1860 Township 9 N 5 W, Henderson County, Illinois - July 5, 1860James Whitney, age 35, Farmer, England
Julia Whitney, age 22, England
Jane, age 6, England
I see that his obituary contains a lot of information, backing up some of the above. I will continue to look tomorrow night.