Steve,
Have you tried to find the church marriage record in St. Louis?
Typically, they would list the parents which would further help
prove the relationship. Additionally, I would look up baptisms,
deaths (especially of the expected father).
I did find them in the 1860 census under "Henry Biner"
In my opinion you have the right one. I did find a "Sophia Hahnholz"
who emigrated in 1851 through New Orleans. Could Hahnholz
be Harnold??
Hope this helps,
Bob Behnen