That's a drop of water on the left cam lobe. Focus instead on the wear at the tips of the cams.
Scary isn't it?
No wonder the tappets looked so bad.
This one was responsible for the worst of the tappets.
Remarkable.
This one was responsible for the second worst of the worn tappets.
Seven out of twelve cam lobes showed at least some wear or pitting.
ugh-ly
This one had the least pitting of all the worn ones.
The worst again.
The end that bolts to the timing chain is supposed to have a brass plug in it according to my mechanic. Here you can see the plug of JB-Weld courtesy of Classic Jaguar!
Here is the other shaft. This is the kind of work you expect from a shade-tree hack, not a well-regarded restoration shop.