What's going on here

[jake650]

Chemical metal has been applied to both ends. Why would someone do that and how do I get this off without damaging the shaft?

I have a replacement head I can use if need be.

[McCabe-Thiele (Ted)]

Looks like a bodge to stop an oil leak or to stop shaft rotation.

If you have a dremel you might be able to start to remove the metal surface - might be worth using a sharp pick tool at the edges where it has been spread onto the cylinder head. It's probably some sort of Epoxy Resin material like JB weld. Some very light impact with a small dead weight mallet might crack the surface contact?

Might be worth some Google searches for a potential solvent first.

If you undo the three bolts on the end cap will this enable the cam top to be removed?
Be easier to work on with the head removed.

[McCabe-Thiele (Ted)]

Looking at my 500 there are what look like three blanking plugs in the casting like the one either side in your photo. Could it be that it's been to stop a leak from the centre plug?

[jake650]

Could well be to stop a leak. It leaks further down between head and block. Prob o ring. Was just curious in case others have done it. I have a new to replace head to solve leaking issues.