bobby131313 is the only moderator that has access to make avatars. I know that he generally does them in "batches" when he has time.
But I'm thrown a little by Dan's note that his "request disappeared from the forum threads a few weeks later"
That is not normal process.
Usually Bobby posts a reply of "done" or locks the thread after he creates your avatar.
Let's try this next... look for your original post in the Support Forum (parent of this thread)http://goscf.com/f/13
When/if you find your original request, open it and 'Post a Reply' to 'BUMP' it to the top of the list.
If your request has really disappeared, feel free to post a new request.