I have done a few of those RTW in 1997/1998/1999.

I beleive the original routing (Flight 1 and 2) back in 1997 was:

EWR-LAX-HKG-DEL-LHR-EWR

DEL was an interesting connecting point from HKG to LHR.

LAX-HKG, LHR-EWR, and LAX-EWR are no longer in service.

The last RTW I did on all UA metals was in 1992 HKG-DEL-LHR-IAD-MIA-SFO-NRT-HKG.

Now with Star Alliance covering the earht, there is really no need for UA offer RTW.

I don't think there are any airlines offer complete RTW services on its own metal.