Please help to decode rims..

[Affe]

My 68 New Yorker has all five rims with the same code so they are surely the original ones.
The date code is very strange..
The M has no plant code but a 7 or 1 beneath...that could be 1967..
Then comes a 28 sideways..not a clue..
Then 8
And last 09

 

[CBODY67]

Unlike GM, which used a two-letter code near the valve stem to ID wheels for particular vehicles and model years, I suspect the codes on a Chrysler wheel are only for wheel plant and vendor ID for warranty issues. They might kind of relate to a particular vehicle's production date, but the main things are the stamp codes on the INSIDE of the wheel, which include the rim diameter, width, and height of the beads (yes, there are industry codes for those too). As in 14x5.5 JK, for example. Might be some other inspection stamps near that, too?

I kind of suspect that some of the stamps near the valve stem hole are for proof of inspections, as the inspection stamps inside the wheel would be obscured by the mounted tire. I believe there are a few in here who might know what the specific stamps mean.

Just some thoughts,
CBODY67