From GabelGuns:

Frank Kuhn is listed as a gunsmith in 1866 at 516 North Front Street in Philadelphia; at 502 Everett Place from 1876-1881; at 476 North Eighth Street from 1881 to 1897 and at 503 North 8th Street in 1900. He is listed as a gunsmith, a dealer in guns and pistols, and as a dealer in sporting goods.

Cheers,

Raimey
rse