I generally treat an amended or corrected SAR as a complete filing of the original SAR. So when I correct or amend I repeat the narrative, but you can copy paste... That may just be me though.
My view is that the corrected SAR should be a one stop shop for LE with the most accurate information.
In life, there is a lot less that could get better and a lot more that could get worse.
MBA Fin/MBS HR
My views only!