I have seen a similar model that holds a different set of drivers.  This is specifically for the Bundhus #10687 metric set from Amazon.  I designed it to be printed in two pieces because at the time I wasn't 100% sure if it would fit on my X1C in one piece.  It requires a 3X6 gridfinity space.  

You could leave the two halves separate, but I CA glued them together using the two included plugs for alignment.  I've also included the one piece design which would have been easier.