If this doesn't make sense, my bad. It is 4AM, and I'm getting ready to go to sleep.
The head gasket can just be wiped down, and stuck back on. That is, if it is in good condition. If it has signs that it was leaking (Soot is a easy sign there), and any kinks are a problem.
When you had the piston out did you look at the rings? I always give them a close look. If the edges of them feel sharp you need rings. Tech Tip- Take some oil and stick it in the cylinder with the head off. Leave it for a while, and come back. If you haven't lost any, or lost very little your not going to have any blow-by issues.
Unless I missed something, what you pictured is the crank shaft, not the cam? Your crank looks fine. All the contacting areas look fine. the light surface rust is on the casting, and areas not contacting anything sensitive. Wire brush, and some degreaser is fine. Just stay away from the area where the connecting rod rides. Which I assume is good? No galling, or metal from the rod stuck to it?
Oh, if your worried about the valves at all you can lap them easy enough. Google should point you in the right direction there. Easy insurance.