Well, I'm glad to throw in my comments today based on how I take care of our cars. If the cylinder is still working, I would not even pull the cam to look at this. However I would take a compression reading while the plugs are out, so I could compare later, when (or if) the situation changes.

Though maybe not totally relevent to this picture, I'd also look carefully at the gaskets both intake and exhaust. My way of looking combines poking at the exposed portion of the intake gasket for brittleness and listening for leaks with a stethoscope around both, especially the underside. In the past, I seem to recall the intake gasket cracking apart on the other end of the motor, but I don't know what would explain that tendency.

No advice here, just how I'd do it and have done it, and I am just a dilettante or a dabbler.
--
Art Benstein near Baltimore

"Wise sayings often fall on barren ground, but a kind word is never thrown away."
-Sir Arthur Helps