Did you oil the capstan bearing and when I do with AMSoil the wow and flutter can be reduced further and I also oil the upper motor bearing with it too under the pulley. The oil I use make a huge improvement in all these bearings. BTW- the motor turning the wrong way can be corrected by takein the cap off back of motor, unsolder the motor terminals and turning the board 180 degrees and resolder it then the motor will go your way that is all there is to it. The abstract regulator system might be used like that if the input voltage to plus of motor was 17Vdc from another regulator as they would be lifting the ground pin by 5 volts so that 17V-5V is 12V at motor. That seems very abstract to me but you never know unless someone tampered with it not knowing what they were doing. A LM7812 would be the more correct regulator feeding the positive of the motor.