Central African Republic dwarfs Oceania: about 620,987 km² km² against 8,600,000 km² km². At true size Central African Republic is about 13.8× larger — the whole of Oceania fits into Central African Republic roughly 13 times.
The old Mercator map treated both about equally (1× vs 1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
Central African Republic fits 13× into Oceania.