Hello Tom, Coleen Flannery of Virginia has been researching the Stephen Marmon line for years.I have not been in touch with her since 2003, but found her eddress on the message boards[probably rootsweb.com/ancestry.com]
I don't know about Stephen Marmon's religious affiliation.All the Marmons I am researching remained Orthodox and some were Anti-Slavery Quakers.
I did find a reference to Stephen "Marmin" serving in the Black Hawk War for a week! in Michigan.[Le Roy Barnett and Roger /Rosentreter/, compiler, Michigan's Early Military Forces (Detroit, Michigan: Wayne State University Press, 2003, p. 202)]
Stephen's death is recorded in the 1880 mortality schedule in Worth, Boone County, Iowa.He was 85, widowed, and died in May.
Finally, there appear to be extant court records, beginning in the Greene County Circuit Court and then on appeal to the Iowa Supreme Court [the latter can be found on Lexis/Nexis database: MARMON v. MARMON ET UX. [NO NUMBER IN ORIGINAL] SUPREME COURT OF IOWA, DES MOINES 47 Iowa 121; 1877 Iowa Sup. LEXIS 217 December, 1877, Decided].This case concerned Stephen Marmon's mental fitness.
Have more info, if you'd like to continue the conversation over email. Debian Marty