My G100 polisher finally gave up the ghost after 25 years. Great polisher over the years. So I am wondering if the backing plate (W68DA) would fit the MT300 polisher. What I saw was that both are 5/16" so I think it will work. Or will I also have to buy a new backing plate? Also I have a bunch of 5" pads, assume they will fit no matter which backing plate works with the buffer?