Your settings seem a little rich to me. Bring your HS needle in to around 3/4 turn and see if that makes a diff in your idle needle setting. If that works then leave the idle there and reset the HS again.
Your parts questions woud be better answered in the www.aomci.org forum. Seems like I was able to find a carb kit for mine not too long ago. Someone will likely have a head gasket for you as well. They are nice running engines! I have two. One I made out of three and the other is a gorgeous one that is in a box waiting to be built. I have all new rings, pistons, complete gasket set and ignition components for it. Should be a stellar engne once built and running.