I started watching ANH, oh the memories of being a kid and watching it

I have a question for anyone who has knowledge. Just how much rotoscoping was used in it. I see a lot of black artifacts which seem to be coming from the rotating reflective blade. In ESB it seems they went to a fully rotoscoped static blade. This makes me think about the top half of of the elstree.
Were they thinking of going to a static rotoscope this early on?
I am leaning towards thinking after all the Tunisa scenes they were thinking of experimenting using a static blade, not necessarily for any more new scenes to come, but to the future possibility of a sequel? Or perhaps for the remote scene they were looking to try this but it failed so they stuck with Ol spinny.
The hero/toe pic it likely being the elstree needed some repairs, a new grip, and probably the bubble strip clamp lever not closing to be sorted.
So we get to repairs: Maybe a new grip was glued on? Maybe the bubble strip dremeled down as you can see plastic slag from rotary sanding and cuts in the elstree bubble strip.
Next the whole welding in a washer? Really need to know if the plastic light bulb stuff was removed before welding. If there is a hole bored through it. Or even if there is melted plastic on the plastic bulb assembly which would indicate they did not remove it and just welded the washer in. If the plastic bulb assembly was removed, the button was probably removed as was the eye and the bunny ears.
Welding in the washer deformed the top part, heat marks can still be seen. The bunny ears wont go back in. So in the end it appears it could be a failed attempt of an experiment.
Now the folmer style knurling on the button can be found on this variant? So it probably belongs to it. But in the toe pic they switched the button to the other type, probably because Roger liked it better.
So after this experiment has been botched and failed, they need to make another hero for when we see it later. They take the button out they like, and someone puts the original back in and stores it. After the movie is done. Clean up time. Someone takes it and lobs it into the Elstree studio junkyard. It hits the ground, the bottom tube hits and damages the edge. Any grips the glue shatters and they fly off. The bubble strip cracks and loses that little section? This seems logical, yet just a theory.