Surfing on the net I found the "North Korea County Handbook". This version was made by the US Marine Corps Intelligence Activity for the Department of Defense "for official use only".
429 pages long, this PDF file contains detailed information on military forces of the DPRK, the tactics, uniforms and rank insignia, TOEs, drawings and photos of weapons and equipment.
Hope it helps (maybe even for a future North Korea Sourcebook) also because this work was made in May 1997.
http://www.dia.mil/publicaffairs/Foia/nkor.pdf