I'm convinced the A30 is legit, and not a 430 as I pitched in post #13.
I have another proposition for this oddity - Slow Payment. The SPD is a "planned" production date, not an actual one. Emphasis on "planned."
When the car is ordered and down payment made at the dealer, I understand the dealer orders the car from Chrysler Corp, and when the car and its options are keyed in to the Chrysler IBM mainframe computer system at the plant, the SPD is calculated. A30 puts this event somewhere near the start of the production year, about Oct 30, 1969.
Side note: A12 and A13 are pretty common SPDs, because dealers tended to order a batch of cars up-front near the start of the model year, with standard options for their showroom floors. I have not confirmed these cars were shipped prior to payment (on credit to the dealer.)
VIN number sequences are assigned on the assembly line, not prior. Generally, the VINs are sequential as the vehicles proceed through the assembly line. So the latter sequence part of the VIN does not get assigned UNTIL its rolling through the assembly line.
Other events may cause a delay in actual production. Among them are parts availability at the plant. But another is delayed payment in full. I believe (unconfirmed) the dealer has some control over when a car is produced, and held back when it isn't paid for.
If the customer-owner took months to pay for their car in full, it seams reasonable it did not roll through the assembly line until much later, perhaps as late as May 1970, as some have suggested. The more "special" the client, the longer the vehicle may have been held in limbo before actual production.
I believe I've seen broadcast sheets and fender tags showing as few as 6 days from the time the car is ordered to when it rolls through the assembly line. But these pics indicate 2-4 weeks between SPD and actual PD.
I recall other examples where the car was but a few days EARLY! So the bottom line is, SPD is a planned date, not an actual one.
Regarding the potential for error, where the A30 was supposed to be 430, I have my doubts. This is not something a data-entry human would normally be typing in manually, and/or potentially mis-reading on a document. I suspect the SPD is calculated by software when the order is keyed in to the computer. The fender tags were printed by a computerized system, so there again, the fender tag stamping operator would not really have the option to introduce human error and screw this up.