At Sept 9/70, the car would have almost certainly had a '70 console instead of '71. Transition was sometime in November for E-bodies. My former 340 shaker ragtop that you restored was Dec '70 build and had the proper '71 console in it.
Lots of carryover for sheetmetal too. '70 PS inner fenders until some point in September. The 383 Shaker R/T you just finished (925 SPD) still had a '70 trunk floor, though it seems that sheetmetal was hit/miss. Almost as if they found an old pallet of '70 metal every so often, and used it up on the line.