I currently own the same set up and would suggest saving your cash until you can afford a major upgrade from the MMT. The wiring change improvement would probably prove to be incrimental at best. I don't know what cartridge you are using but you would probably achieve a temporary solution via upgrade in this area.
Up grade Sumiko MMT
I have a Sumiko MMT that works fine but am wondering if rewiring it is a good investment or just go with a better arm? It is on a Sota Saphire TT. The rest of the system is "high end" with Wilson WP7's. I have a large record collection but with a daughter at the U of Mich, disposable money is hard to come by. Any experience or suggestions will be appreciated. Denny