Any HANDS on experience good or bad with these? I have all the factory info but got a guy wanting to trade me a NIB for one of my AK's and trying to find out things like is the Back strap metal or Plastic? Is the hammer Cast or not. There is no room for cast parts in my 1911's so I'm trying to find out ahead of time what all I may have to change. I never seen a handgun that didn't shoot straight so dont need any accuracy opinions. Just looking for accurate info from those that would know (OWNERS) This would be info I know I can trust because your not trying to sell me one. This guy wants an answer pretty quick or he will just put it up for sale and I know it wont last long then. So any help would be greatly appreciated...Thanks.