Date code on Road Wheels

[bc3j]

Looking for help on identifying the production date of my Road Wheels. No build sheet, LA plant car. Spare steel wheel seems to be from Motor Wheel plant 3, 11-3-69. SPD on fender is 123. Car is a 1970.  Attached is two pictures trying to capture the markings for an ID. The letter preceding the wheel size is an "L".

[6bblgt]

the M1/9 = Motor Wheel Corp. plant #1 (Lansing, MI) 1969

look around the valve stem or on the outside of the rear lip for a date stamping 

[bc3j]

Thanks. I looked but could only find "2944474" stamped by the valve stem. Nothing inside other than the pictures. Could the "L" mean November and the "3" on the left of the top row mean the third day of the month? Just guessing.