Decoder for the rest of the info on fender VIN tag?

[MRGTX]

This forum has offered up the specifics on decoding VIN tags many times and that's very useful. What about the rest of the information?

The fender tag on my Dart has 4 lines:

R11 EN1
FE5 U A88 B43 G33 M21
FE5 F4X9 000 A10 125303
F44 D34 LL29 G3B 174861

From the VIN, I can see that it's a "low" price class Dart Sport, 1973, 318 egngine Hamtramck, MI...no surprises.

What do the other digits mean? Is there a decoder out there?

Thanks!
-Mike