Here's some pictures of the cam bearing and camshaft I removed yesterday.
I'm going to remove the head today and will have a better idea if there's other damage.
If the remainder of the head appears o.k., is this repairable? Considering the lack of availability of these heads is it worth attempting a repair?
It appears the stud that's in the piece that's broken off could be removed, the threaded portion of the hole could be drilled out a little, a longer stud could be drilled and tapped into the head (below the broken off piece) where there's still about an inch of cast aluminum. Once it's all in place and the top cam bearing tightened down it may still work. Or am I hopefully dreaming?