It is not supposed to look like that. There is supposed to be flat surface for the thrust bearing to ride on. 

I have a couple of ideas. You could have a machinist turn it down to a flat surface, and then make a washer to take up the space that was created by the machining. You could also have it welded up, and turned back down, but since it is cast iron, that might not go so well.

There is also a fellow in Texas by the name of Kent Gordon who has several Super 55 and 550s disassembled for parts. He'd probably have a good one. You can email him at <!-- e --><a href="mailto:kgteinc@yahoo.com">kgteinc@yahoo.com</a><!-- e --> or call him at 903-729-8349.

You might have trouble finding a new thrust bearing to go on the surface there. Maybe someone has come up with a replacement, but we ended up finding a used bearing to get our Super 55 back together.