Originally Posted by Dan333SP

The top bearing pops out, the bottom cartridge on the fork crown also pulls off but I think the bearing seals and cartridge came apart because the top pulls off with the ball bearings visible and covered in rust, but the angled metal inner part of the bearing remains on the fork almost as if it's seized to the aluminum steerer. I guess I can soak that part in oil and slide it off?

Both upper and lower cartridge bodies are so rusted that I can't see the measurements. I haven't even ridden the bike in the rain all that much (maybe 10 times in 3 years?) but I've read elsewhere that this issue is common on my bike, maybe just poorly designed seals. I'll keep digging around to see if I can find the exact measure for my bike.