I sold my F-Body and bought a 1971 Satellite about a month ago.

Here's the fender tag info.
M21 M25 R11 END
GY8 C 22 B51 G33 J31
GY8 H2XW TX9 225 B51162
E44 D31 RH23 G1R 21xxxx

Can someone tell me what the codes mean?
Many Thanks!