Help Dating Celestion G12T-75's

[shortfuse]

In the 3 images attached is pic G12T-75  1 0r G12T-75  2 older.  I know the G12T-75  3 is the newest version.
I have 2 JCM 800 cabs the Bottom is filled with the Pic #1 and the Top is filled with the Pic #2.  Pic #1 black label with white stripe in center sounds warmer than the Pic #2 White or Silver label which are much brighter with less bottom.
Which should be in the cabs or did they both come out in the 80's.  Which is the oldest?  My guess the silver labels as they look like my Rola 65's which were made in the 70's but sound nothing like them.
Help please.

[shortfuse]

No celestion guru's out there?

[rafe]

center ones are same as the ones in my 84 jcm800....The other two ....Look like newer graphics to me

[sluckey]

Does this help?

http://www.unclespot.com/celestion_date_codes.html

[shortfuse]

Steve thanks
The date coder table may help I will double check the housing #ers & letters my next trip home.

Rafe
  I have an 84 top cab loaded with those (middle pic) also but the bottom cab which is an 82 cab is like the pic at the top.  So I plan on trying to date each with the code chart link.  Maybe they both came out in the 80's but man they sound completely different.
The Pic at the bottom is the newest version which are the ones made in China.