Hi Bob I don't think what you said was wrong. I think others are more meticulous in their approach.
The fact that your mowers give you good service is evidence that your method works.
I am taking the block to a fellow who is going to see if a hone will sort it out for me. He seems to think, as people have said here that it is a build up of piston material in the bore moreso than gouging of the iron. To me it feels gouged though.
Cheers
