intake cam rusty and rough on lobes...WTF?

I popped the valve cover on my 91 RS and the intake cam has rough rust on the contact part of the lobe…any ideas?? the head gasket was blown and I’m currently inspecting for crack in block. Is it simply the water in there that ate the smoothness right off of there? I’m picking up a b18b1 head tonight anyway…just curious.

Just use sand cloth or send them out to be refinished/