Toro Timemaster 30 - bad piston and cylinder

on my 3rd summer with the time master 30 and have not had any of the reported issues yet. However, the piston has gouged the cylinder wall and both will need to be replaced. I have opened up the engine and know what is needed, however, I cannot find any location online that sells the parts...as well, I cannot find a cross reference to let me know which B&S engine model this mower is using.



Any help would be appreciated.