Mystery Comstock

Desperately trying to figure out where my Comstock family connection is.  My brick wall is documenting and locating my 4x great grandfather's, Coleman Comstock, parents and/or siblings.  I hope to also locate his wife's, Lydia Bush Walker Comstock, parents as well as any siblings, if possible.    I am a pretty novice with research so there may be something else those with more experience can help locate.   My search begins with:        

My great grandmother, Mary Ellen "Mollie" Comstock.  b. July 7, 1889, Audubon Co., IA; d/o Allen Bush Comstock, b. Jan 31, 1860, Decatur Co., IA d.1925;  s/o Geo W. Comstock b.Jun 6, 1832, Jackson Co., Indiana d.Mar 4, 1863, Civil War; s/o,

Coleman Cumstock (Comstock) and Lydia Bush Walker Comstock.  Conflicting info regarding state of birth of Coleman -- reference to TN and NJ both.   Index located for marriage to Lydda Walker, Knox Co., KY, May 21, 1821.  Have located a reference to a business license secured by Coleman Cumstalk Dec 5, 1821 at Barbourville, secured by "Joseph Eve and Samuel Vanney."  Listed on a tax list in Knox Co., KY, 1828.  Also located documentation of a tract of land known as the

Coleman Cumstock tract lying on the middle fork of Richland Creek, Knox, KY, adjoining Nathaniel and James Curtis and another Tract upon which

Frethias Parman, deceased, lived on the 8th of October 1840.  I have seen the data on rootsweb but was hoping to locate additional documentation/evidence to rely on as to lineage of Coleman and Lydia.    Any help greatly appreciated.