I thought about trying this a little while back. You would want to get firm dimensions of the 2013 hatch size because the main problem I see, though Im not positive on dimensions of the hatch, deals with the scupper holes on the older boats. IMO without measuring, the newer hatch is too wide (you will hit the scuppers when cutting the hold to accomidate it). The scupper holes appear to have been moved on the new 2013 edition (havent seen one first hand just in pictures) making room for a wider hatch while on the old 2012 and before models the scupper holes surround the center hatch, one on each corner. So either find a way to cut and cap the scuppers on the boat (I don't think I would try that) or custom make your own center hatch like hobie has.
Interesting porject, let us know if you come up with anything.