"Hi Randy, I'm not sure of the exact street addresses, but these two murals are on opposite sides of the street on 1st Avenue, in the short block between Eight & Ninth Streets (south of Tucson High). cheers, Warren"
Update (September 18, 2012): The top mural is gone. It used to be on the front of 218 S. 1st Avenue. The other mural (shown in two halves) is in good shape.