Going back to the original query, I recall both the L1011 and DC10 No. 2 engines were definitely inclined about 4 degrees tail down. I recall being told it was (on the DC10) to equalise the pitching moments due to thrust changes between the underslung wing engines and the high mounted tail engine however this could have been folklore. It could equally have been to align the nacelles and exhaust flows with local airflows much like the wing engines are toed-in slightly on most or all widebodies so the pylons and nacelles are aligned with the slightly angled airflow in cruise caused by the bow wave off the nose.
L1011 No. 2 fairing
The "Frisbee" fairing (named after its designer) was a redesigned fairing for the splitter area under the lip of the No. 2 intake, principally to reduce drag, but it also reduced airflow noise in the rear cabin. It originally appeared on the L1011-500 but I think it was offered for retrofit to all