Blackcat,
The gun system isn't too bad. You've got the cannon, two suspension arms and the ammo chute to contend with. Here are a few reference photos and some info on the M230 cannon system that may be of some help in your build.
http://tri.army.mil/LC/CS/csa/apm230.htm
http://tri.army.mil/LC/CS/csa/ah64gun5.jpg
The kit does not come with the wire-strike frame around the cannon, if you want a current machine, you'll have to scratchbuild that with styrene rod.
I don't have access to my instruction sheets right now (they're in Dallas, I'm in NY) but I hope this helps.
Enjoy!