If not, then does anyone know how to convert PAL to NTSC without quality loss?
Strictly speaking you can't, since NTSC has less lines than PAL, but all you need to do is resize the video from 720x576 to 720x480 in whatever editor you use, and change the framerate from 25fps to 23.976fps.
Your best source might be that PAL digital TV grab that someone posted the original Shaw-ghost scene from RoTJ from.
David