12 bolt decoding

[Knightrider]

So I decoded my rear end, all but the last digit.

 

Code is CKD 0323B1 (the 1 is upside down?)

 

So I understand this is Chevy 2.73 gearing built march 23 in buffalo, but what is the upside down 1?

 

Any reason to keep the rear end just for originality's sake? Was going to get a moser assembly, but now I'm considering having this one rebuilt how I want it.

[MonteCarLois]

1st shift.