Comeliness was developed for use in the book Deities & Demigods AFAIK. That was definitely the first place it appeared in print in a D&D book. At least at the time I assumed it was intended to help portray elements of these mythical creatures that the basic stats didn't cover well (at least in the author's opinions). I don't believe it was described there as a general 7th ability score to be applied to PCs. That depiction came later in UA, which came out about the same time as OA (as you point out). I haven't gone and dug for Dragon 67, its packed away in my garage, lol, so not sure if it was just an article about gods of WoG or if it discussed PCs.
Close.
1e Deities and Demigods has rules on page 7 for expanding Charisma up to 25 and down to -7 with super high and low Charisma having an awe/horror mechanic that was very much based on the divine nature of the being.
Here is the text of the horror mechanic for negative charisma.
In certain instances, some divinities are so loathsome and repellent as to actually have negative charisma. This applies only to the truly ghastly divine beings. The horror which their appearance and presence inspires causes creatures in the hit dice or level range noted below to be stunned with fear and detestation until the being is no longer in sight. While in this condition a creature can do nothing but defend itself physically against attacks. As with awe power, even if a person were to be given negative charisma through some terrible curse or change, he or she would not acquire the horror ability. The reaction of the average creature to a hypothetical non-divine being with a negative charisma would be a desire to kill it immediately.
Charisma Score Reaction Adjustment Horror
-1 -40% Up to 1 HD/level
-2 45 Up to 2 HD/levels
-3 50 Up to 4 HD/levels
-4 55 Up to 6 HD/levels
-5 69 Up lo 8 HD/leveIs
-6 65 Up to 10 HD/levels
-7 70 Up to 12 HD/levels
This is a bit different in description and mechanics from comeliness.
In Dragon 67 (I have the CD archive so it is easy to pull out) the article called Loyal Readers is on page 67 and is Gygax responding to readers' letters and then discussing comeliness.
Here is the beginning of the Comeliness discussion.
A BEAUTIFUL IDEA
Frank Mentzer and Francois Marcela-Froideval are already hard at work, and I am being flooded with suggestions and ideas from these Good Gentlemen. Francois uses a “Beauty” attribute for his characters, and I have come to the conclusion that you might also like to use such a rating. Here are my thoughts:
Comeliness is my word for the attribute. Beauty is too specific, as it calls to mind a positive state of good looks. “Comeliness” has a more neutral connotation; i.e., a character with a 3 attribute score for Beauty would be a non-beauty, but a 3 in Comeliness implies ugliness.
Comeliness is not charisma. Charisma, however, can affect comeliness. After the six attributes of a character are determined, his or her looks must be determined. Is the character ugly, homely, plain, or pretty? This characteristic is determined by the comeliness roll. 3d6 are rolled and totalled. The resulting number, between 3 and 18 inclusive, is modified:
It then discusses a -25 to 30 range of scores. I have not compared it side by side with the WOG, UA, OA charts to compare specifics but high charisma has a charm effect and then if you reject someone their reaction becomes as if the comeliness was negative but half the score.