(...) All of your type-"2" lines need to be changed to type-"5" _conditional_ lines. That is the way to do "edges" for "curved" surfaces in LDraw. For a example of type-"5" lines, look at the promitives for a Cylinder (1-4cyli.dat) and a Sphere (...) (24 years ago, 31-Oct-00, to lugnet.cad.dat.parts)