Found a solution for my broken NXA crankcases...a beautiful '05 5KE TZ 250 (less than 600 miles total), tons of spares, Marvic forged magnesium wheels, VHM heads, revalved suspension...enough pistons, cranks and crankcases for the next 5 years.
Would like to post a photo but don't know how!

Still looking for a set of crankcases for my NXA though...it will make an excellent rain bike!