The late H.J. Swinney's five volume set on New York makers says: SWEENEY, JOHN Geneva "Starkey, Bloomfield, Dundee" ca. 1820-24 in Geneva, later in others.
His obituary . . . (1886). born in the township of Severn, Ontario County, NY. June 19, 1804 . . .learned the gunsmiths's trade in Genevea and afterwards ran a gun shop in Starkey, Bloomfield and Dundee. In 1833 he removed to Ann Arbor, Michigan. Later, 1838, became an innkeeper & gained a great reputation at that calling. . . He must have been apprenticed to Castle Southerland about 1820. Since Southerland moved to Ann Arbor before 1842 - possibly some time before - his move may somehow be associated with John jSweeney's being there"
So, Mr. Old Ford, I thank you for inspiring me to look this up. Seems like I might have an addition to make to my revised second edition of Michigan Gunsmiths, currently in progress.