I could go over again what I know about it,but I would recommend you scroll down to a conversation about a 1660 rotor RandR on July 31,and then work your way back up when the topic came up again. Important thing is to be safe. You may end up spending more nickels and dimes on things when you get it apart and can really examine things inside,but now is the best time to do it.Don't be cheap now and sorry later.