N97 - Noise reduction package
Y39 - Special order
F58 - RR C/M reinforcement / welds (rear crossmember??)
F72 - single key package
H51 - A/C
J52 - Inside hood release
M25 - sill moldings
N41 - dual exhaust
GY8 Roof Paint Code: Gold Leaf Metallic
U - U.S. Specs
B42 - HD disk drakes ??with 11" rear drums??
B51 - Power brake
F13 - HD alternator 60 AMP
F38 - roof reinforcement
GY8 Paint Code: Gold Leaf Metallic
L - Low
2 - Vinyl Bench
T3 - Light Tan
GT8 - upper door frame Paint Code: Tahitian Walnut Metallic
428 SCheduled Production Date: Wednesday 4 / 28 / 1971
VON: vehicle order number J132N1 ??N?? must be reading wrong
E65 - 383-4 Barrel (only 1 4bbl engine was available in B & E-bodies in '71)
D32 - 727 TorqueFlite Trans
RK - Plymouth Belvedere Police
41 - 4 Door Sedan
N - 383 300HP 1-4BBL 8 CYL
1 - 1971
G - St. Louis, MO, USA

M25 is "simply" sill mouldings - it appears the mouldings were possibly STD on the FLEET '71 Plymouth b-bodies.