[1] The company resulted from the partnership of the creative stained glass window designer Oliver Speers Kimberly (1871–1956) and Francis ("Frank") Joseph Duffner (1860–1929), born in Cleveland, Ohio, who had more than 20 years of experience in the lighting industry.
In 1888, Adler left the firm to found a competing enterprise, and Joseph Duffner sold his interest to Bermingham (who was still listed as President of the company in 1900).
He changed employment again in 1901, and became a manager with The Plume and Atwood firm, a Waterbury, Connecticut, concern which manufactured brass rivets, nuts, and bolts, as well as kerosene lamps.
He worked there a short time before he left to enter a partnership with Thomas Calvert (1873-1961), a transplanted Englishman and also one of Tiffany's artists.
They hired as their chief designer Gazo Foudji (1853–1916), also known in contemporary sources as Fudji and Fudjiyama, who was a famous Japanese artist of the period and a graduate of the Ecole des Beaux-Arts.
A large, early example of his stained glass windows, dating from 1910 while he was employed by the Duffner & Kimberly firm is found in Grace and Holy Trinity Cathedral, the cathedral church of the Episcopal Diocese of West Missouri, located in Kansas City, Missouri.
Kimberly successfully managed this company until sometime between 1923 and 1926, when he finally closed the stained glass firm and moved to Norwalk, Connecticut.
Mr. Kimberly married a second time after the death of his wife and returned to New York City, where he died on February 25, 1956, after a long illness.
Francis Joseph Duffner died of a heart attack while at his desk in his office at The Rolled Plate Metal Company, in New York City, on June 11, 1929.