Stuart:
Cold War Kit is too broad a term. The Cold War lasted for 50 years and saw a clothing evolution from WWII Battle Dress to OG107 Combats. What you are looking for is 1980s combats and field equipment. There is no book on this topic although John Cameron's on-line MP Museum has a lot of information that you can draw upon. Perhaps you might be better off getting a maniquin and dressing it in the clothing and equipement of the era and standing it beside your Iltis rather then attempting to play the part as a re-enactor.
ED
http://mpmuseum.org/