I've partially disassembled the rear wheel. When I got the lockring off, I expected the cassette to slide off. Instead, the two smallest cogs came off, followed by the jagged washer/spacer shown at the far left in the photo of small parts below. The rest of the cassette doesn't seem to want to come off.

I can say this with confidence. The problem is neither a broken axle or destroyed bearing. Axle is out and is fine. Bearings are out on the drive side and are fine. Whatever is wrong is within what remains on the wheel.

So, questions...

Is this something other than a standard freehub/cassette? If the cassette is just stuck, what is the procedure to get it off without damaging something?

The following is a photo of the freehub and cassette remaining on the wheel...



The following photo shows the small parts that came off of the wheel. From right to left: 1) Lockring; 2) Gasket; 3) Smallest cog; 4) Next to smallest cog; 5) Spacer/washer sitting between cog 5 & 6.