Ran across this while digging for Southgate info. tanzleman, of course, is correct, no one can discuss the rifle's value without seeing it. Anyway, here is some misc info from a recent book on Michigan gunmakers:
Bowlby, G. W., Village of Pontiac 1853 - 186752
Oakland County. Prop'r Kentucky rifle shop, Saginaw. Granted patent on combined rear sight and cartridge ejector for firearms, May 21, 1867 No. 64,94112. In the 1860 census he is a Gun Smith, born in New Jersey about 1824, wife Catherine born ~1826 in Massachusetts. In 1860 his household consisted of George, age 8 and Chauncey Clark, age 22, a grocer, both born in Michigan. Rather successful, the value of his real estate in 1860 was $3000, personal estate $2000.
Brian Russell, of 4th Street Books, Royal Oak, has provided the following information: The Pontiac city directory of 1860—61 lists: Bowlby, G.W., proprietor Kentucky rifle shop, between Pike and Andrew, residence Garland. The county directory of 1886 indicates Catherine Bowlby, widow of George W., lived in her own house at the corner of Park and Cottage, Pontiac.
The Pontiac Weekly Gazette, for February 8, 1878 includes: Death of George W. Bowlby: The city was startled on Wednesday afternoon, by the report of the sudden death of George W. Bowlby, at his home on Park street. He has been ailing and looking badly for some months, but there were no indications of near or sudden dissolution. On Wednesday forenoon he was about the city as usual, and rode out with his wife, but returned between one and two o’clock feeling very sick, and immediately lay down and summoned a physician. He rapidly became worse, expiring in a few hours. The disease was determined to be abscess of the liver. Mr. Bowlby was born in Warren County, New Jersey, February 19. 1823, came in to Pontiac, 1853, and engaged in the gunsmith business for fifteen years. He was a quiet estimable man and a good citizen. His funeral will take place from his residence on Park St. this Friday afternoon at one o’clock.
The Pontiac Weekly Bill Poster for February 13, 1878 reported: The funeral services of the late Geo. W. Bowlby were held at his residence on Parke Street last Friday afternoon, sermon by Rev. J.M. Gelston, and the remains interred at Oak Hill. The cause of his sudden death was determined to be abscess of the liver, instead of heart disease. Mr. Bowlby came to Pontiac in 1853, and soon opened a gun shop, in which business he remained some fifteen years. He was nearly fifty-five years old, and a good citizen. Sermon by Rev. J.M. Gelston
One of his breech-loading rifles is shown in The GunReport May 1980 page 4.