Finally got some time to do some test prints again, and here they are!
Attachment 8420
Attachment 8421
I actually had to print these using the left extruder (still not figured out how to stop the extruder from going too far left when cancelling a build); right one still seems clogged even though I left it in pure acetone for at least 3 days!
As you can see the circle is almost perfect now, just a few imperfections which may now be down to the slicer and speed.
I got the bearing in only after hammering it in pretty hard. But I guess this piece is also designed to be like that to keep it in once in.
But as you can see after forcing it in, it's looks like a perfect fit!
So next question is how to loosen the bar so I slip these on? Note I have plastic pulleys on mine as well.