I thought this mention of a Baltimore company - Cooper Macdonald - was interesting. Anyone know if they are still around?
"The management of Fairchild Engine & Airplane Corp. decided to divest themselves of the AR-15 rifle. License to produce the AR-15 was acquired by Colt’s Patent Fire Arms Manufacturing Co., Inc. The firm of Cooper-MacDonald, Inc., Baltimore, Md., was selected to promote the AR-15 rifle in the United States and certain foreign countries. Extensive efforts have been made by Cooper-Macdonald to interest the military forces of friendly nations in southeast Asia, where the small stature of the people makes a small, light rifle especially attractive."