A fellow over at TC gave me this info. Thot some of you may be interested as well:
http://www.unionlabel.org/dobuy/tires.asp
This site indicates which manufacturer and which plant (and which Union no.) is indicated by the first 2 ltr code following "DOT". In my case the tire with "MD" is for the Goodyear plant in Gadsden, AL made by USWA Local Union No. 12L. The "MU" indicated on the rest of the tires on my car are not called out at this website. I was told these tires were original to the car.
The TC dude also stated: "The date code is the last three digits. An example code of 228 indicates that a tire was made in the 22nd week of 1998."
My response to this was: "As far as the date code goes, how do you differentiate the year of manufacture since they only use one number to represent the year? i.e. 228= 22nd week of 98, or 88, or 78 or, etc."
Will keep you posted.
Sam