Rim dating

[fireguyfire]

I came across a set of magnum 500 rims and I am considering putting them onto my 69 charger.
Here is a photo of the stamping on the rim. If I remember correctly the number on the bottom left ( is the year the rims were made, 1968.
Is that correct?

[Kern Dog]

A 5 1/2" wheel when you can fit double that in the car?   

[Alaskan_TA]

The M1 with 0 under it is;

Motor Wheel Plant 1 - 0 Last digit of year it was made.