I apologize if this has been posted before, however, I came into interest in building (putting together) my own AK. My question though is, are there any already made Receivers for the AK? I was looking for one that was already bent and drilled. My question also is, if they are available, what tools will I need to put the rifle together? My main interest was to put together a Yugoslavian AK. Thanks for any help or advice you guys could give me.