M28 is just the code for the huge front fender moldings, a 71 only option.
A91 was the WSS option PACKAGE. It included rim blow steering wheel, woodgrain non-rallye dash, vinyl top, belt & front valance moldings, pedal dress-up, F&R bumper guards, rallye wheels and S.E. style rear taillight panel. These cars were basically S.E.'s without the small rear window.
Does your car have ANY of these options? I'm guessing you have no BC sheet either, eh?
If it has a small rear window, then it probably has the A78 "Formal Roof" option. Coincindentally, A78 was the WSS option on 69 Darts!
If your car had fixed quarter windows, then it was a Deputy, code A93.
Body side moldings are V5_(insert color here)
Vinyl top is V1_
WOM's are M26
Steve