This is my 4th or 5th PCV replacement and the first where I did not get vacuum at the oil filler cap. All of the engines had the same amount of miles.

Yes, I cleaned out the oil return holes, which weren't totally clogged but were easily cleaned out. I immediately switched to synthetic 10W30 in an attempt to 'clean' the internals. It is time for another oil change.

No, I didn't blow air into the block. I wonder if I could blow air into the hose at the cam cover (easily accessed) with the oil cap on and see if I get back pressure.

The initially 'black' exhaust pipe is now 'clean', so I suspect that the valve stem seals are in reasonably good condition. My MPG is not as good as I would like, 22mpg around the suburbs, no road trips yet.

I could also pour some Marvel Mystery oil in each cylinder and let it soak over night and give the rings a shot. I could borrow a pressure tester and check the compression, never have done a leak down test.
--
Keeping it running is better than buying new