Here are a few more facts from my dusted records:

Pan's numbers for its SFO-HKG flights were PA 5 and PA 6. United kept the numbers 5 and 6 and called them 805/806.

It appears people still cannot get around the fact that TPE was a mini focus city for UA in early 90s. Yes, they did have TPE-SEL, TPE-MNL and TPE-BKK. I am not sure about TPE-SIN, though. I have never seen or heard UA ever offered that route.

Yes, UA did fly NRT-TPE in the early 90s.

DC-10-30 has the range from West Coast to NRT (even to China). MU flew from SHA/PVG to the West Coast for a while in the 90s. Its range is about 6,700 miles (5,900nm)