I own a 162SE. Runs great! Always has. But it is LOUD. Need to order the complete muffler assy including the 2 threaded studs & nuts. At the parts manual look-up page on your site, it lists about 10 different manuals for my model number. Different manuals show different parts numbers. How do I identify which is appropriate? The local dealer is of no help. He says parts information is no longer available and he wants me to provide the parts numbers.