Believe it or not, how about the Thai Worldwide Timetable (hardcopy)? I have an old one (10/26/08 - 3/28/09), they're listed in the back along with all their code shares. Anyway the ones operated on UA metal run from TG 5502 to TG 5703.

If you wanted to get a copy, it seems the only places where TG has ticket offices in the US are NYC and LAX. Or maybe it's available online in Acrobat format?