Absolutely right the original plinth was made to fit the Thorens arm which is quite shallow, in contrast not only is the 3009 arm deeper but on many versions the cable is attached at the very bottom of the arm, even after modifying the arm the plinth has barely enough space to allow suspension travel, i think the original plinth is about 50 or 60mm deep, i'd say if you're going to the expense of a new plinth it needs to be about twice as deep, mine for instance is 100mm with an 18mm MDF base board the 3009 arm fit's well and allows easy set up of the suspension