It looks like there is some sort of collar there. I would be wire brushing it to see if you can spot a difference where the diameters differ.
I would be wondering if you can get that pulley to go further up the crank toward the engine. Clean the shaft (with emery or a file) Heaps of WD or CRC. See if it will go up, even just a 1mm.
With the chattering that the lower one has done on the crank i would expect that there will be a nice burr on the crank at the bottom of the pulley you are trying to remove.
You might need to consult a parts list to see if there are any extra holdy on bits.
Bob.
