Chris,I went to Rutgers, New Brunswick 1969-1973. Remember driving past the factory at least thru 1974. This is the building at 120 Georges Road. You can still see the name in faded white paint.
https://goo.gl/maps/zJbqkM9Hrv72
Always bought Black Diamond strings to support local business.
Found this also:
http://theunofficialmartinguitarforum.yuku.com/topic/44073/Black-Diamond-Strings#.VgbiUZfgyL8