Dorr N. Wiltse, Jr and I wrote the book Michigan Gunsmiths While googling my own book I found there were a couple of posts on this forum, one from a CMWill, looking for information on John O'Mara. All I have is:
O’Mara Bros., Detroit 1865 - 18708
Wayne County. Reported to have made a three barreled gun, two rifle bbls. over one shotgun barrel.
O’Mara, John, Detroit 1863 - 18708
Wayne County. In 1865 - 1864. with Frederick Ege at 113 Griswold. In the 1866 - ’67 directory9 John O’Mara is listed as an engraver, working and living in the house at 8 Michigan Avenue. A three-barreled gun, two rifled, one shotgun, exists.
A note by CMWill said that O'Mara had been with Wingert in 1855-56, I did not know this & would like to have the original reference. For 3rd edition, Insha'Allah.
This book has become my replacement (well, not entirely . . . ) for gun collecting & it is a continuing work. I'm in Rochester, Michigan and yes, Jim Marsh knows me. He gave me photos of a nice double by Quillin for the book.