Problem started out of the blue about a week ago. Car still started, but would grind with the starter engaged.
After a couple days, I also noticed I was feeling pulsations in the clutch while cranking.

That starter stopped engaging on Thursday, so I was forced to swap in a new one. Did everything I could to line it up, and it still grinded like a mofo.

So, I spent many hours last night trying to align the starter properly and regardless of how I do this, it still grinds.
I have the correct starter plate for my tranny, but there's a little give left and right.

No teeth are missing from the flywheel. Some are a little chewed up, but the general shape is still there. Nothing out of whack, just wear marks.
I checked the old starters gear, and they were all chewed up. The new starter has about 20 starts on it, and the gears are still fine.

Ideas?