A good thing to do in the Kangaroo is lowering the turbine thrust line, opening the fuse top (like pictured above 16 years ago, yikes) and adding two blocks of reinforced balsa with plywood, using plenty of filler to do nice filets that will improve airflow and appearence. By doing this you can use a standard turbine mount on it not to mention that the plane will fly better too.
Dont worry about the extra weight doing this or even installing the turbine back a inch or two.