I like the idea of a mis-stamping, and I suspect that
@69CoronetRT also will.
Here's my GUESS and nothing more due to lack of data to support my theory (ANOTHER reason to save
every tag, window sticker and broadcast sheet possible)
Some 70's codes for package cars and body styles get a little wonky.
For example:
70 Barracuda and Challenger Coupe cars carry the BS23 and JH23 hard top VIN code on the tag but also the A93 coupe package code on the tag instead of a typical 21 Coupe body style designation. The coupe body style is actually coded as a package would be.
70 Sport Fury GTs Carry the PH23 VIN but the A52 'package' code an also a PP23 designation.
70 S23 cars carry a PH23 VIN but an A51 'package' code and PS23 designation.
It's as if certain A codes in 1970 indicate a 'super' package code where normal package parameters are exceeded and virtually change the body style and/or model designation of the car.
Without any other verification, I'm wondering of the A74 code is such a designation for the DM VIN.
Do we have any other A74 cars that are NOT DM cars?
Do all DM cars code A74?
Does anyone else remember the thread where I asked about the 70 Dodge C body production numbers? I think this very topic was the root cause for them not balancing. We could not reconcile the Custom numbers as they were accounted for differently due to the A74 code (I can't find the thread).
You also have to consider the A71 (Polara Special) and A77 (Monaco only???) packages may fall under this same line of thinking. They are Super packages in some way.
IF this is the correct possibility for the decoding, then we have to take another look at the F* VIN cars that pop up now and then and take another look at why they code F* and are, maybe, not typos but indeed an actual specific model designation.
Take aways:
ALWAYS, ALWAYS, ALWAYS, take the time to snap pictures of fender tags and look for broadcast sheets and window stickers in any junk yard cars, cars you part out or at car shows. Every piece of information is valuable in some way.
A lot of published information or 'common belief' is incomplete or erroneous. Research is ongoing.