A couple of observations:
When Luke first gets the lightsaber from Obi-Wan, he turns it on and then there is a weird kind of halo or distortion around his arm. I assumed that is ws from the roto-scoping, but I am not 100% sure. I did not notice it elsewhere when sabers were used.

I will help possessed on that one, He used my EP IV beta 1.2 in which I did all of the Sabers and Blasters, The Luke Obi scene was not finished, the Halo was an attempt to erase the original sabers with painting out all of the frames with a clean plate. I did not want to roto on top of what was there because it would look too thick and silly. Also it was the intent to fix c3po from moving as there was a jump cut when Luke activated his saber. I never finished that scene… It was as is, as I ran out time to complete it. For the shots inside the falcon, I used a CC wire remover tool, that squeezed in the original sabers and roto-ed on top of that rendered sequence. If you stare at it, yes you can see a little warpiness to it, But if you kickback with a beer and popcorn. Most can not tell.