Guys, To complete the "dog box" passenger kit built set I an making, I need to modifiy a whitemetal chassis to fit the driver carraige. The trailers are already complete. I have modified a HO Athearn F7A Super PWA S P Daylight, removed the motor, extended the driveshafts, and fitted it perfectly to the new chassis, and runs beautifully, however the new chassis is too wide for the kit body. What is the best way to narrow a whitemetal chassis? I have a dremel. I need to take about 2mm off each side. Thanks, TOOT!