The World War II era 1911s look better and more authentic with the full rainbow scratch !I prefer the full rainbow scratch across the slide.
You have to rotate it because of the slide stop.Do you have to rotate the take down pin? I don't own a 1911,but my semi autos just align the pin after its halfway inserted.
I removed the scratch from mine with a Scotchbrite pad, of course it's a stainless 1911.
I try to avoid the scratch as it would bug the crap out of me.
Try using a guitar pick or a thin piece of plastic (like your driver license to set the slide stop.)