From Cornell Publications
LINK
The index to Breechloading Shotguns 1860-1940 Vol. I A-F by Joseph T. Vorisek (Cornell Publications) shows these four
Folsom, Charles
Folsom, EA
Folsom, H. & D. Arms Co.
Folsom, N.D.
From the Yale Banner of 1885 page 256 on Crown Street
LINK
From the Yale Banner 1890 page 13 (now on Church Street)
LINK
From PGCA
http://www.parkerguns.org/forums/showthread.php?t=683
From these I gather N.D. Folsom is a company in its own right
Was located in New Haven, CT
113 Crown Street then 5 Church Street
Okay, coffee is brewed. Gotta get a cup.
Cheers,
Jack