Potato Man by Megan McDonald illustrated by Ted Lewin*

A grandfather shares with his grandchildren a period of time where he made some poor choices and how he choose to change.
The potato man was the new huckster.  His one eyed face which was lumpy like a potato scared the children on East Street.  Unfortunately the boys choose to act cruelly towards him.  Then the main character (the grandfather as a boy) has the chance to make amends.
Strategy: asking questions
*Borrowed from the library.
*Highly recommend.