Should a St. Louis nonprofit agency that helps the poor have any business in rebuilding the diesel engine of an old Mississippi River tugboat named the Bryant T? That’s essentially the question raised in a recent federal audit of a Grace Hill Settlement House program to retrofit diesel engines and reduce pollutants from delivery trucks, school buses, fire engines and even two old tugboats in St. Louis. The audit recommended the agency return more than $1.4 million to the Environmental Protection Agency.