The trouble with online decoders is that they do not catch sequence or typographical mistakes. Check this out, I entered it to test that decoder;
Decoding of Fender Tag: Botttom to Top, Left to Right
Code Description
D21 Heavy Duty 4-Speed Manual Transmission
D21 Heavy Duty 4-Speed Manual Transmission
JH21 J = Dodge Challenger
H = High
21 = 2 Door Coupe
D21 D = Unknown
2 = 1972
1 = Lynch Road, MI, USA
100001 Sequence Number '100001'
D21 Paint Code: Heavy Duty 4-Speed Manual Transmission
PRX9 Trim Grade/Style/Color
P = Premium
R = Vinyl and Leather Bucket Seats
X9 = Black
D21 Upper Door Frame: Heavy Duty 4-Speed Manual Transmission
D21
Q00001 Order Number: Q00001
D21 Roof Type OR Color: Heavy Duty 4-Speed Manual Transmission
D21 Heavy Duty 4-Speed Manual Transmission
D21 Heavy Duty 4-Speed Manual Transmission
D21 Heavy Duty 4-Speed Manual Transmission
D21 Heavy Duty 4-Speed Manual Transmission
D21 Heavy Duty 4-Speed Manual Transmission
D21 Heavy Duty 4-Speed Manual Transmission
D21 Heavy Duty 4-Speed Manual Transmission
EN2 End of Codes Assembly Line 2
Comments;
JH21 - None exist.
No Challengers were made at Lynch Road.
PRX9 is a Plymouth code and so on.
Sooner or later someone may make an accurate online decoder, but I will not hold my breath.
T/Ake care,
Barry