If it were me, I would take it to a machine shop and have it Zyglo checked for cracks just to be sure, given it was leaking so badly into the crankcase. It could be hairline cracks that aren't obvious to the naked eye that may widen at operating temp. Also have it checked for warpage as usual. Other than that, it's just cleaning, cleaning, cleaning, as mentioned above, and reinstalling the head with a fresh gasket. I wouldn't worry too much about the rust around the base of the studs. Just clean it out. It's probably moisture leaking by the gasket. Some had suggested to me to use the copper gasket spray on the head gasket when I did it. I used it and have had no problems. I would recommend it as a little extra insurance. Just a light coat...
Interesting fact you might notice is the cylinder head is a bit softer and easier to nick with the blade while cleaning. I believe only the block is cast in the Alusil alloy. It feels a bit harder and dulls blades quicker.
Any WYIT plans? Lap the valves, new valve stem seals, etc. Personally, I'm very obsessive about cleaning caked on oil crud to make the motor look as well cared for as possible and those pics make me cringe a little. No better reward for fixing leaks than seeing it stay clean. Perfect chance to do it.
Good luck!