Finally got some primer on the right quarter.
I was talking about the center row of holes.
The SS uses 3 trim pieces on the rear of the trunk and is drilled for only the upper and lower row of holes like on the quarters beside it. The center insert is held on by the upper and lower trim pieces. The Impala has a one piece trim and is drilled for only the center row of holes. Yours has all 3 rows. I had to replace my trunk lid 3 years ago and could only find an Impala lid. The body shop drilled the upper and lower rows and filled the center row. I drilled the holes for the SS emblem on the upper right after I got the car home.