Need help with decoding fender tag on a 1972

[Meep-Meep]

My books go to 71 but I found that most of the codes make sense. Still would like to be sure on a few, specifically on the B51 (next to the U). This is for a buddies Challenger that he just bought and I thought I'd help him find out what it is. I think it's originally a tripple black car looking at the TX9 codes. And no, he's not selling it. Thanks.

 

[Meep-Meep]

Here is the tag

 

[detmatt1]

My book shows power brakes. Let me know if you have questions on any of the other codes.

 

[Meep-Meep]

Thanks Matt! And I may have more questions.