Here's what I know for certain about Orrin: b.1829, NY moved to IA in 1854, according to 1856 IA census m.Angeline W. Morlan 22 July 1854 in Dallas County, Iowa d.1858, Greene County, IA Daughter Lavina said her father was from MI in 1880 census. She also gave his name as Aaron, but he spelled it Orrin in 1856 census.
Possibly significant: An Orrin Yeomans appears in Orleans, Ionia County, MI in the 1850 census. He was born in NY, and is in the household of a John Yeomans b.1790. Problems: He's b.1824 (age given as 26) and he's got a wife and three sons. Wife and sons could've died before move to IA, but age is tougher to reconcile.