This business was originally established as Archer, Pancoast & Company, in 1859, the co-partnership consisting of Ellis S. Archer, William C. Ellison and George Pancoast. From a modest beginning, the operations of business steadily grew, and in a few years it had won a national reputation for the artistic excellence of its products. In 1868, the business had increased to such extensive proportions that a stock company was organized and incorporated under the laws of New York State, with a capital of US$300,000. The mammoth factory and warehouse were located at No. 67 Greene Street, extending through to Nos. 68, 70, 72 and 74 Wooster Street. The factory was arranged and equipped with the modern machinery and appliances, the majority of which were specially designed and built for these works. A force of 350 skilled mechanics was employed at one time. Each department was under the management of a manager, and the whole was regulated by a system which both facilitated business and assured the prompt execution of orders.
Archer &  Pancoast mfg co.
This is the model that became the Convex reflector of 1864 , featuring a rectangle fount and triangular shaped frame. 

Brass push in bayonet  lock no.1 sangster  burner is marked J. SANGSTER patent March 25, 1862  on the thumbwheel. 

Back of the reflector panel is stamped PATENT APP. FOR
Meaning they released this model before holding the patent rights of design from the U.S. Patent office 
In April of 1863 , the smaller of the Convex models was patented , I believe this model was made sometime in 1862 to that date .

Condition  - excellent for its age, barn fresh untouched.
Clean tin , no  heavy rusting or pitting present. 
Glass panels are in good condition with no cracks .
No visible condition issues present. 

** has not been oil tested **

** will be shipped with glass panels removed and packed separately **